WO2011077388A1 - Modification of enzymatic crosslinkers for controlling properties of crosslinked matrices - Google Patents

Modification of enzymatic crosslinkers for controlling properties of crosslinked matrices Download PDF

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Publication number
WO2011077388A1
WO2011077388A1 PCT/IB2010/056008 IB2010056008W WO2011077388A1 WO 2011077388 A1 WO2011077388 A1 WO 2011077388A1 IB 2010056008 W IB2010056008 W IB 2010056008W WO 2011077388 A1 WO2011077388 A1 WO 2011077388A1
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Prior art keywords
matrix
enzyme
modified
polymer
peg
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PCT/IB2010/056008
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French (fr)
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Orahn Preiss-Bloom
Guy Tomer
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Lifebond Ltd
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Priority to JP2012545517A priority Critical patent/JP5796860B2/en
Priority to ES10814706.7T priority patent/ES2551388T3/en
Priority to DK10814706.7T priority patent/DK2515957T3/en
Priority to US13/517,906 priority patent/US9066991B2/en
Priority to CN201080057151.0A priority patent/CN102711853B/en
Priority to CA2782863A priority patent/CA2782863A1/en
Application filed by Lifebond Ltd filed Critical Lifebond Ltd
Priority to EP10814706.7A priority patent/EP2515957B1/en
Priority to BR112012015029A priority patent/BR112012015029A2/en
Priority to AU2010334412A priority patent/AU2010334412B2/en
Publication of WO2011077388A1 publication Critical patent/WO2011077388A1/en
Priority to IL220325A priority patent/IL220325A/en
Priority to US14/696,390 priority patent/US10202585B2/en

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    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12NMICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N9/00Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/10Transferases (2.)
    • C12N9/1025Acyltransferases (2.3)
    • C12N9/1029Acyltransferases (2.3) transferring groups other than amino-acyl groups (2.3.1)
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L24/00Surgical adhesives or cements; Adhesives for colostomy devices
    • A61L24/04Surgical adhesives or cements; Adhesives for colostomy devices containing macromolecular materials
    • A61L24/08Polysaccharides
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L24/00Surgical adhesives or cements; Adhesives for colostomy devices
    • A61L24/04Surgical adhesives or cements; Adhesives for colostomy devices containing macromolecular materials
    • A61L24/10Polypeptides; Proteins
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L27/00Materials for grafts or prostheses or for coating grafts or prostheses
    • A61L27/14Macromolecular materials
    • A61L27/20Polysaccharides
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L27/00Materials for grafts or prostheses or for coating grafts or prostheses
    • A61L27/14Macromolecular materials
    • A61L27/22Polypeptides or derivatives thereof, e.g. degradation products
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P7/00Drugs for disorders of the blood or the extracellular fluid
    • A61P7/04Antihaemorrhagics; Procoagulants; Haemostatic agents; Antifibrinolytic agents
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K14/00Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/435Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • C07K14/78Connective tissue peptides, e.g. collagen, elastin, laminin, fibronectin, vitronectin, cold insoluble globulin [CIG]
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12NMICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N9/00Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/10Transferases (2.)
    • C12N9/1025Acyltransferases (2.3)
    • C12N9/104Aminoacyltransferases (2.3.2)
    • C12N9/1044Protein-glutamine gamma-glutamyltransferase (2.3.2.13), i.e. transglutaminase or factor XIII
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00Medicinal preparations containing peptides
    • A61K38/16Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • A61K38/43Enzymes; Proenzymes; Derivatives thereof
    • A61K38/45Transferases (2)
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L17/00Materials for surgical sutures or for ligaturing blood vessels ; Materials for prostheses or catheters
    • A61L17/06At least partially resorbable materials
    • A61L17/08At least partially resorbable materials of animal origin, e.g. catgut, collagen
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L2400/00Materials characterised by their function or physical properties
    • A61L2400/04Materials for stopping bleeding
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12YENZYMES
    • C12Y203/00Acyltransferases (2.3)
    • C12Y203/02Aminoacyltransferases (2.3.2)
    • C12Y203/02013Protein-glutamine gamma-glutamyltransferase (2.3.2.13), i.e. transglutaminase or factor XIII

Definitions

  • Enzyme crosslinked matrices are formed in a variety of applications in the food, cosmetic, and medical industries.
  • enzyme crosslinked hydrogels are widely used in a variety of medical applications including tissue sealants and adhesives, haemostatic preparations, matrices for tissue engineering or platforms for drug delivery. While some hydrogels such as gelatin and poloxamer may be formed as a result of physical interactions between the polymer chains under specific conditions, e.g change in temperature, most polymer solutions must be crosslinked in order to form hydrogels.
  • implantable hydrogels In addition to the actual formation of the solid gel, implantable hydrogels must be resistant to the conditions that are prevalent in the tissue where they are applied, such as mechanical stress, temperature increase, and enzymatic and chemical degradation.
  • crosslinking may be done outside the body by pre-casting or molding of hydrogels. This application is used mainly for tissue engineering or drug delivery applications. Alternatively, crosslinking may be done inside the body (in situ gelation or cross linking) where a liquid solution is injected or applied to the desired site and is cross linked to form a gel.
  • Gel formation can be initiated by a variety of crosslinking approaches. Chemical approaches to gel formation include the initiation of polymerization either by contact, as in cyanoacrylates, or external stimuli such as photo-initiation. Also, gel formation can be achieved by chemically crosslinking pre-formed polymers using either low molecular weight crosslinkers such as glutaraldehyde or carbodiimide (Otani Y, Tabata Y, Ikada Y. Ann Thorac Surg 1999, 67, 922-6. Sung HW, Huang DM, Chang WH, Huang RN, Hsu JC. J Biomed Mater Res 1999, 46, 520-30. Otani, Y.; Tabata, Y.; Ikada, Y.
  • Cross-linking of a mussel glue was initiated by the enzymatic conversion of phenolic (i.e., dopa) residues of the adhesive protein into reactive quinone residues that can undergo subsequent inter-protein crosslinking reactions (Burzio LA, Waite JH. Biochemistry 2000, 39, 11147-53. McDowell LM, Burzio LA, Waite JH, Schaefer JJ. Biol Chem 1999, 274,20293-5).
  • the enzymes which have been employed in this class of sealants are tyrosinase on one hand and laccase and peroxidase on the other hand which acts by forming quinones and free radicals, respectively from tyrosine and other phenolic compounds. These in turn can crosslink to free amines on proteins or to similarly modified phenolic groups on proteins and polysaccharides.
  • a second cross-linking operation that has served as a technological model is the transglutaminase-catalyzed reactions that occur during blood coagulation (Ehrbar M, Rizzi SC, Hlushchuk R, Djonov V, Zisch AH, Hubbell JA, Weber FE, Lutolf MP. Biomaterials 2007, 28, 3856-66).
  • Biomimetic approaches for in situ gel formation have investigated the use of Factor XUIa or other tissue transglutaminases (Sperinde J, Griffith L. Macromolecules 2000, 33, 5476-5480. Sanborn TJ, Messersmith PB, Barron AE. Biomaterials 2002, 23, 2703-10).
  • mTG calcium independent microbial transglutaminase
  • Sakai et al. found that a larger quantity of covalent cross-linking between phenols was effective for enhancement of the mechanical stability, however, further cross-linking between the phenols resulted in the formation of a brittle gel. (Sakai S, Kawakami K. Synthesis and characterization of both ionically and enzymatically crosslinkable alginate, Acta Biomater 3 (2007), pp. 495-501)
  • cofactor-dependent crosslinking enzymes such as calcium-dependent transglutaminase
  • removing the cofactor, by binding or otherwise, after a certain reaction time can limit the degree of crosslinking.
  • cofactor removal is frequently not technically feasible in hydrogel formation where the hydrogel may trap the cofactor.
  • cofactor-independent enzymes such as transglutaminases available from microbial origin
  • limited degrees of crosslinking can be obtained by heat treatment of the reaction system.
  • such a treatment induces negative side effects on protein functionality and is therefore undesirable to apply.
  • not all reaction systems are suitable to undergo heat treatment.
  • crosslinking enzyme released into the body can interact with body tissues and cause local or systemic damage.
  • crosslinked composition which could be used for a wide variety of applications.
  • the present invention in at least some embodiments, overcomes the above described drawbacks of the background art, and provides a solution to the above technical problems (among its many advantages and without wishing to provide a closed list), by providing a matrix or hydrogel that is formed by enzymatic crosslinking of polymers wherein the crosslinking enzyme molecules have been modified for the purpose of improving the crosslinking density, mechanical properties, or other properties of the matrix, and/or to provide improved control over the rate and/or extent of crosslinking.
  • An optional method of altering the enzyme molecules is by modifying the perceived volume of the enzyme molecules in the crosslinked matrix being formed. The modified perceived volume is preferably determined according to the extent of crosslinking of the polymers to form the matrix, such that decreased extent of
  • crosslinking as compared with extent of crosslinking with unmodified enzyme molecules, indicates increased perceived volume.
  • One method of increasing the perceived volume of the enzyme molecules is by increasing the size and/or the hydrodynamic volume of the molecules by covalent or non- covalent attachment of at least one molecule or moiety to the enzyme molecules.
  • the inventors have demonstrated that the degree of enzymatic crosslinking in hydrogels or crosslinked matrices can be regulated by covalent attachment of molecules to the enzyme such that the modification of the enzyme molecules result in a lower ultimate level of crosslinking. In this manner, the phenomenon of excessive crosslinking can be prevented.
  • Another method of increasing the perceived volume is through modification of the electrostatic charge of the enzyme molecules such that their net charge is of opposite sign to the net charge on the polymer or co-polymer chains. This can be achieved by changing the isoelectric point (pi) of the enzyme.
  • Perceived volume or “effective volume” as defined herein refers to the effective hydrodynamic volume of the crosslinking enzyme inside the crosslinked matrix.
  • the perceived volume may be increased by covalent or non-covalent binding of the enzyme to another molecule, carrier, polymer, protein, polysaccharide and others, prior to the crosslinking reaction or during the crosslinking reaction.
  • “Diffusion” or “Mobility” as defined herein refers to the random molecular motion of the crosslinking enzyme or other proteins, in solution, hydrogen, or matrix that result from Brownian motion.
  • Diffusion coefficient refers to a term that quantifies the extent of diffusion for a single type of molecule under specific conditions.
  • a non-limiting example of a proxy for measuring enzyme diffusion is by measuring the elution of enzyme from a hydrogel.
  • Reduced Mobility refers to a slower molecular motion or smaller diffusion coefficient of a protein or enzyme in a solution or inside a hydrogel.
  • Size refers to the molecular weight or hydrodynamic volume or perceived volume of a molecule.
  • MW Molecular weight
  • MW refers to the absolute weight in Daltons or kilodaltons of proteins or polymers.
  • MW of a PEGylated protein ie - protein to which one or more PEG (polyethylene glycol) molecules have been coupled
  • MW is the MW sum of all of its constituents.
  • Hydrodynamic Volume refers to the apparent molecular weight of a protein or enzyme that may usually be measured using size exclusion chromatography.
  • the hydrodynamic volume of a constituent refers to the diameter or volume the constituent assumes when it is in motion in a liquid form.
  • Microx refers to refers to a composition of crosslinked materials.
  • the composition that includes these materials transitions from a liquid state to a gel state, thereby forming a "gel,” “hydrogel” or a “gelled composition.”
  • the gel can have certain viscoelastic and rheological properties that provide it with certain degrees of durability and swellability. These materials are often polymers.
  • the matrix may contain materials which are not crosslinked, sometimes referred to as co-polymers.
  • Polymer as used herein refers to a natural, synthetic or semi-synthetic molecule, containing a repeatable unit.
  • Co-polymer refers to a constituent of the matrix which may or may not participate in the crosslinking reaction and is usually not the main constituent of the matrix.
  • a non-limiting example comprises polysaccharides such as dextran and/or a cellulosic polymer such as carboxymethyl cellulose.
  • the co-polymer is preferably not covalently bound to the enzyme or to the matrix material, such as the protein base of the matrix.
  • Carrier refers to a polymer, a protein, polysaccharide or any other constituent which binds the crosslinking enzyme covalently or non-covalently, either before or during the crosslinking reaction.
  • Crosslinking Enzyme refers to an enzyme or combination of enzymes that can either directly (e.g. by transglutamination) or indirectly (e.g. through quinone or free radical formation) crosslink substrate groups on polymer strands into a coherent matrix, such as a hydrogel.
  • a cross-linked matrix comprising a substrate polymer crosslinked by a modified enzyme molecule, said modified enzyme molecule having a modification that alters a perceived volume of the enzyme molecules in the crosslinked matrix as the matrix is being formed through cross-linking of said polymer.
  • said modified enzyme molecule has a modification that increases an actual size of said modified enzyme molecule.
  • said modified enzyme molecule has a modification that increases a hydrodynamic volume of said modified enzyme molecule.
  • said modified enzyme molecule has a modification that modifies an electrostatic charge of said modified enzyme molecule to be of opposite sign to a net charge of said substrate polymer by changing the isoelectric point (pi) of said modified enzyme in comparison to unmodified enzyme.
  • said modification is of the ⁇ - amino group of lysines of the enzyme through a process selected from the group consisting of succinylation (with succinic anhydride), acetylation (with acetic anhydride), carbamylation (with cyanate), reductive alkylation (aldehydes) and treatment with maleic anhydride.
  • said modification is of one or more side chains containing carboxylic acids of the enzyme to decrease the number of negative charges.
  • said modification comprises covalent or non-covalent attachment of at least one molecule or moiety to said modified enzyme molecule.
  • said modification comprises covalent attachment of a modifying molecule to said modified enzyme molecule.
  • said modified enzyme molecule has a reduced diffusion rate and a reduced cross-linking rate in comparison to non-modified enzyme, but has at least similar measured enzyme activity in comparison to non-modified enzyme.
  • Optionally reduced cross-linking rate is at least 10% of the non-modified enzyme cross -linking rate.
  • said modifying molecule comprises a carrier or polymer.
  • said polymer comprises a synthetic polymer, a cellulosic polymer, a protein or a
  • said cellulosic polymer comprises one or more of
  • said polysaccharide comprises one or more of dextran, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, hyaluronic acid or a starch derivative.
  • said modifying molecule comprises PEG (polyethylene glycol).
  • said PEG comprises a PEG derivative.
  • said PEG derivative comprises activated PEG.
  • said activated PEG comprises one or more of methoxy PEG (mPEG), its derivatives, mPEG-NHS, succinimidyl (NHS) esters of mPEG (mPEG-succinate-NHS), mPEG- glutarate,-NHS, mPEG- valerate-NHS, mPEG- carbonate-NHS, mPEG- carboxymethyl-NHS, mPEG- propionate-NHS, mPEG- carboxypentyl-NHS), mPEG- nitrophenylcarbonate, mPEG-propylaldehyde, mPEG-
  • mPEG-NHS methoxy PEG
  • NHS succinimidyl
  • mPEG-carbonylimidazole mPEG-isocyanate
  • mPEG-epoxide mPEG-epoxide
  • said activated PEG reacts with amine groups or thiol groups on said enzyme.
  • the molar ratio of said activated PEG to lysine residues of said activated enzyme is in a range of from 0.5 to 25.
  • said activated PEG is monofunctional, heterobifunctional, homobifunctional, or multifunctional.
  • said activated PEG is branched PEGs or multi-arm PEGs.
  • said activated PEG has a size ranging from 1000 dalton to 40,000 dalton.
  • the matrix further comprises a co-polymer that is not covalently bound to said enzyme or to said substrate polymer.
  • said co-polymer comprises a polysaccharide or a cellulosic polymer.
  • said polysaccharide comprises dextran, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, hyaluronic acid or a starch derivative.
  • said cellulosic polymer comprises carboxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, methyl cellulose.
  • said modified enzyme molecule is modified by cross-linking said modified enzyme molecule to a plurality of other enzyme molecules to form an aggregate of a plurality of cross-linked enzyme molecules.
  • a modification or an extent of modification of said modified enzyme molecule affects at least one property of the matrix.
  • said at least one property is selected from the group consisting of tensile strength, stiffness, extent of crosslinking of said substrate polymer, viscosity, elasticity, flexibility, strain to break, stress to break, Poisson's ratio, swelling capacity and Young's modulus, or a combination thereof.
  • an extent of modification of said modified enzyme determines mobility of said modified enzyme in, or diffusion from, the matrix.
  • said modification of said modified enzyme reduces diffusion coefficient of said modified enzyme in a solution of said modified enzyme and said protein or in a matrix of said modified enzyme and said protein, in comparison to a solution or matrix of non-modified enzyme and said protein.
  • an extent of modification of said modified enzyme determines one or more matrix mechanical properties.
  • said modified enzyme molecule shows a greater differential of crosslinking rate in crosslinked polymer than in solution as compared to non-modified enzyme molecule.
  • a method for controlling formation of a matrix comprising modifying an enzyme molecule with a modification that alters a perceived volume of the enzyme molecules in the crosslinked matrix as the matrix is being formed; mixing said modified enzyme molecule with at least one substrate polymer that is a substrate of said modified enzyme molecule; and forming the matrix through crosslinking of said at least one substrate polymer by said modified enzyme molecule, wherein said forming the matrix is at least partially controlled by said modification of said enzyme molecule.
  • said modification reduces a crosslinking rate of said modified enzyme molecule as an extent of crosslinking of said at least one substrate polymer increases.
  • said modified enzyme molecule and said at least one substrate polymer are mixed in solution, such that said modification controls extent of crosslinking of said at least one substrate polymer as a viscosity of said solution increases.
  • said modifying comprises PEGylation of the enzyme at a pH in a range from 7 to 9.
  • pH of the PEGylation reaction is 7.5 -8.5.
  • said at least one substrate polymer comprises a substrate polymer selected from the group consisting of a naturally cross-linkable polymer, a partially denatured polymer that is cross -linkable by said modified enzyme and a modified polymer comprising a functional group or a peptide that is cross-linkable by said modified enzyme.
  • said at least one substrate polymer comprises gelatin, collagen, casein or albumin, or a modified polymer, and wherein said modified enzyme molecule comprises a modified transglutaminase and/or a modified oxidative enzyme.
  • said at least one substrate polymer comprises gelatin selected from the group consisting of gelatin obtained by partial hydrolysis of animal tissue or collagen obtained from animal tissue, wherein said animal tissue is selected from the group consisting of animal skin, connective tissue, antlers, horns, bones, fish scales, and a recombinant gelatin produced using bacterial, yeast, animal, insect, or plant systems or any type of cell culture, or any combination thereof.
  • said gelatin is of mammalian or fish origin.
  • said gelatin is of type A (Acid Treated) or of type B (Alkaline Treated).
  • said gelatin is of 250-300 bloom.
  • said gelatin has an average molecular weight of 75-150 kda.
  • said modified transglutaminase comprises modified microbial transglutaminase.
  • said modified polymer is modified to permit crosslinking by said modified microbial transglutaminase.
  • said modified oxidative enzyme comprises one or more of tyrosinase, laccase, or peroxidase.
  • said matrix further comprises a carbohydrate comprising a phenolic acid for being cross-linked by said modified oxidative enzyme as said at least one substrate polymer.
  • said carbohydrate comprises one or more of arabinoxylan or pectin.
  • said enzyme molecule is modified through PEGylation and wherein said PEGylation provides immunogenic masking by masking said enzyme molecule from an immune system of a host animal receiving the matrix.
  • said host animal is human.
  • a method for sealing a tissue against leakage of a body fluid comprising applying a matrix as described herein to the tissue.
  • said body fluid comprises blood, such that said matrix is a hemostatic agent.
  • a hemostatic agent or surgical sealant comprising a matrix as described herein.
  • compositions for sealing a wound comprising a matrix as described herein.
  • a use of the composition for sealing suture or staple lines in a tissue is provided.
  • composition for a vehicle for localized drug delivery comprising a matrix as described herein.
  • composition for tissue engineering comprising a matrix as described herein, adapted as an injectable scaffold.
  • a method of modifying a composition comprising: providing a modified enzyme having a cross -linkable functional group and a protein having at least one moiety cross-linkable by said modified enzyme; mixing said modified enzyme and said protein, wherein said modified enzyme cross-links said protein and is also cross-linked to said protein through said cross -linkable functional group.
  • Non-limiting examples of direct crosslinking enzymes which directly crosslink substrate groups on polymer strands, include transglutaminases and oxidative enzymes.
  • transglutaminases include microbial transglutaminase (mTG), tissue transglutaminase (tTG), and Factor XIII. These enzymes can be from either natural or recombinant sources. Glutamine and lysine amino acids in the polymer strands are substrates for transglutaminase crosslinking.
  • Non-limiting examples of oxidative enzymes are tyrosinase, laccase, and peroxidase. These enzymes crosslink polymers by quinone formation (tyrosinase) or free radical formation (laccase, peroxidase). The quinones and the free radicals then interact with each other or with other amino acids or phenolic acids to crosslink the polymers.
  • the crosslinkable substrates for these enzymes may be any proteins which contain tyrosine or other aromatic amino acids.
  • the substrates may also be carbohydrates which contain phenolic acids such as freulic acid. Such carbohydrates may be arabinoxylan or pectin, for example.
  • Synthetic or partially synthetic polymers with one or more suitable functional groups could also serve as cross-linkable substrates for any of the above enzymes.
  • Polymer strands or “Polymer chains” as defined herein refers to the substrate polymer for enzyme crosslinking, which according to at least some embodiments of the present invention, preferably belongs to one of the below categories (as non-limiting examples only and without wishing to provide a closed list):
  • any polymer with substrate groups that are naturally crosslinkable by the enzyme and that is itself naturally crosslinkable by the enzyme would include protein or polypeptides such as gelatin, collagen, and casein which are naturally crosslinkable by the enzyme.
  • Polymers natural or synthetic, that are not substrates for enzyme crosslinking but that have been modified with peptides or functional groups which are substrates of the enzyme, thus rendering the modified polymer crosslinkable by the enzyme.
  • Non-limiting examples of such polymers include any suitable type of protein, which may for example optionally comprise gelatin as noted above.
  • Gelatin may optionally comprise any type of gelatin which comprises protein that is known in the art, preferably including but not limited to gelatin obtained by partial hydrolysis of animal tissue and/or collagen obtained from animal tissue, including but not limited to animal skin, connective tissue (including but not limited to ligaments, cartilage and the like), antlers or horns and the like, and/or bones, and/or fish scales and/or bones or other components; and/or a recombinant gelatin produced using bacterial, yeast, animal, insect, or plant systems or any type of cell culture.
  • protein that is known in the art, preferably including but not limited to gelatin obtained by partial hydrolysis of animal tissue and/or collagen obtained from animal tissue, including but not limited to animal skin, connective tissue (including but not limited to ligaments, cartilage and the like), antlers or horns and the like, and/or bones, and/or fish scales and/or bones or other components; and/or a recombinant gelatin produced using bacterial, yeast, animal, insect, or plant systems
  • gelatin from animal origins preferably comprises gelatin from mammalian origins and more preferably comprises one or more of pork skins, pork and cattle bones, or split cattle hides, or any other pig or bovine source. More preferably, such gelatin comprises porcine gelatin since it has a lower rate of anaphylaxis.
  • Gelatin from animal origins may optionally be of type A (Acid Treated) or of type B (Alkaline Treated), though it is preferably type A.
  • gelatin from animal origins comprises gelatin obtained during the first extraction, which is generally performed at lower temperatures (50-60° C, although this exact temperature range is not necessarily a limitation).
  • Gelatin produced in this manner will be in the range of 250-300 bloom and has a high molecular weight of at least about 95-100 kDa.
  • 275-300 bloom gelatin is used.
  • a non-limiting example of a producer of such gelatins is PB Gelatins (Tessenderlo Group, Belgium).
  • gelatin from animal origins optionally comprises gelatin from fish.
  • any type of fish may be used, preferably a cold water variety of fish such as carp, cod, or pike, or tuna.
  • the pH of this gelatin (measured in a 10% solution) preferably ranges from 4-6.
  • Cold water fish gelatin forms a solution in water at 10° C and thus all cold water fish gelatin are considered to be 0 bloom.
  • a high molecular weight cold water fish gelatin is optionally and preferably used, more preferably including an average molecular weight of at least about 95-115 kDa. This is equivalent to the molecular weight of a 250-300 bloom animal gelatin.
  • Cold water fish gelatin undergoes thermoreversible gelation at much lower temperatures than animal gelatin as a result of its lower levels of proline and hydroxyproline.
  • cold water fish gelatin has 100-130 proline and 50-75 hydroxyproline groups as compared to 135-145 proline and 90-100 hydroxyproline in animal gelatins (Haug ⁇ , Draget KI, Smidsr0d O. (2004). Food Hydrocolloids . 18:203-213).
  • a non-limiting example of a producer of such a gelatin is Norland Products (Cranbury, NJ).
  • low endotoxicity gelatin is used to form the gelatin solution component of the gelatin-mTG composition.
  • a gelatin is available commercially from suppliers such as GelitaTM (Eberbach, Germany).
  • Low endotoxicity gelatin is defined as gelatin with less than 1000 endotoxicity units (EU) per gram. More preferably, gelatin of endotoxicity less than 500 EU/gram is used.
  • gelatin with endotoxicity of less than 100 EU/gram is preferred, gelatin with less than 50 EU/g is more preferred.
  • Gelatin with endotoxicity less than 10 EU/g is very expensive but could also be used as part of at least some embodiments of the present invention in sensitive applications.
  • type I, type II, or any other type of hydrolyzed or non-hydrolyzed collagen replaces gelatin as the protein matter being cross-linked.
  • Various types of collagen have demonstrated the ability to form thermally stable mTG-crosslinked gels.
  • a recombinant human gelatin is used.
  • Such a gelatin is available commercially from suppliers such as
  • Recombinant gelatin is preferably at least about 90% pure and is more preferably at least about 95% pure. Some recombinant gelatins are non- gelling at 10° C and thus are considered to be 0 bloom.
  • a high molecular weight recombinant gelatin is preferably used, more preferably including a molecular weight of at least about 95-100 kDa.
  • the cross-linkable protein preferably comprises gelatin but may also, additionally or alternatively, comprise another type of protein.
  • the protein is also a substrate for transglutaminase, and preferably features appropriate transglutaminase- specific polypeptide and polymer sequences.
  • These proteins may optionally include but are not limited to synthesized polymer sequences that independently have the properties to form a bioadhesive or polymers that have been more preferably modified with transglutaminase- specific substrates that enhance the ability of the material to be cross-linked by transglutaminase. Non-limiting examples of each of these types of materials are described below.
  • transglutaminase target for cross-linking have been developed that have transition points preferably from about 20 to about 40°C.
  • Preferred physical characteristics include but are not limited to the ability to bind tissue and the ability to form fibers.
  • these polypeptides may optionally be used in compositions that also feature one or more substances that lower their transition point.
  • Non-limiting examples of such peptides are described in US Patent Nos. 5,428,014 and 5,939,385, both filed by ZymoGenetics Inc, both of which are hereby incorporated by reference as if fully set forth herein. Both patents describe biocompatible, bioadhesive, transglutaminase cross -linkable polypeptides wherein transglutaminase is known to catalyze an acyl-transfer reaction between the ⁇ -carboxamide group of protein-bound glutaminyl residues and the ⁇ -amino group of Lys residues, resulting in the formation of 8-(y-glutamyl) lysine isopeptide bonds.
  • the resultant composition is used as a vehicle for localized drug delivery.
  • the resultant composition is an injectable scaffold for tissue engineering.
  • the composition is a hemostatic composition. According to some embodiments, the composition is a body fluid sealing composition.
  • compositions of the present invention preferably provide rapid hemostasis, thereby minimizing blood loss following injury or surgery.
  • "Wound” as used herein refers to any damage to any tissue of a patient that results in the loss of blood from the circulatory system or the loss of any other bodily fluid from its physiological pathway, such as any type of vessel.
  • the tissue can be an internal tissue, such as an organ or blood vessel, or an external tissue, such as the skin.
  • the loss of blood or bodily fluid can be internal, such as from a ruptured organ, or external, such as from a laceration.
  • a wound can be in a soft tissue, such as an organ, or in hard tissue, such as bone.
  • the damage may have been caused by any agent or source, including traumatic injury, infection or surgical intervention. The damage can be life-threatening or non-life- threatening.
  • Surgical wound closure is currently achieved by sutures and staples that facilitate healing by pulling tissues together.
  • sutures and staples that facilitate healing by pulling tissues together.
  • Such devices and methods are needed as an adjunct to sutures or staples to achieve hemostasis or other fluid-stasis in peripheral vascular reconstructions, dura reconstructions, thoracic, cardiovascular, lung, neurological, and gastrointestinal surgeries.
  • Most high-pressure hemostatic devices currently on the market are nominally, if at all adhesive.
  • the compositions of the present invention overcome these drawbacks and may optionally be used for hemostasis.
  • Figure 1 Effect of reaction pH and activated PEG concentration on PEGylation products size and distribution;
  • Figure 2 Effect of reaction time and pH on size and distribution of PEGylation products
  • Figure 4 Elution of mTG and PEGylated mTG from the same crosslinked gelatin gel
  • Figure 5 Elution of mTG (left) and PEGylated mTG (right) from different crosslinked gelatin gels
  • FIG. 6 Burst pressure values for gelatin sealant made with non-PEGylated mTG and 2 types of PEGylated mTG;
  • FIG. 8 SDS-PAGE analysis of PEGylation products of horseradish peroxidase (HRP);
  • Figure 10 SDS-PAGE analysis of PEGylation products of mTG, where the reactive PEG is a bifunctional lOkD PEG-NHS;
  • Figure 11 shows mass to charge spectrum of a typical batch of PEGylated mTG acquired by MALDI-TOF mass spectrometer.
  • Figure 12 shows SDS-PAGE analysis of PEGylation products of mTG where PEG reagent to amine ratio is kept constant but reactant concentration is varied.
  • the catalytic rate of a crosslinking enzyme within a crosslinked matrix can also be controlled through control of the perceived volume of the enzyme molecule.
  • such control can optionally and preferably lead to reduced catalytic rate of crosslinking as the matrix approaches a desired mechanical state, by increasing the perceived volume of the enzyme molecule prior to initiation of the crosslinking reaction or during the reaction itself.
  • the solidifying matrix traps the size-enhanced enzyme at the desired crosslinking density state and further crosslinking is prevented.
  • Perceived enzyme volume is a function of enzyme molecular weight and hydrodynamic volume, among other factors.
  • the ultimate extent of crosslinking within a crosslinked matrix can be limited by engineering the enzyme molecules, the matrix material, the crosslinking environment, or some combination of these factors to increase the perceived volume of the enzyme molecules within the crosslinked matrix as the matrix is formed. Without wishing to be limited by a single hypothesis, it is possible that increased perceived enzyme volume results in reduced mobility of the enzyme in the crosslinked matrix. Reducing enzyme mobility to control ultimate crosslinking density is most effective when the enzyme molecules maintain mobility at the early crosslinking reaction stages when the solution viscosity is still low, but lose mobility as crosslinking progresses to increase the solution viscosity, and lose mobility more severely after the initial solid matrix or hydrogel has been formed.
  • crosslinked matrix is increasing the effective size of the enzyme molecules. This can be accomplished by increasing the enzyme molecule molecular weight (MW),
  • hydrodynamic volume or both MW and hydrodynamic volume. This is a preferred method because it should not affect the structural composition of the crosslinked matrix.
  • enzyme molecule size is preferably increased in a manner that does not eliminate enzyme activity or its ability to crosslink the desired polymer substrate into a solid matrix or hydrogel.
  • the enzyme also preferably retains sufficient activity to form the matrix within an appropriate amount of time.
  • the size-enhanced enzyme molecule also preferably retains sufficient mobility within the crosslinked matrix to catalyze the desired degree of crosslinking prior to ceasing mobility within the matrix.
  • JPET 234 250-254, alpha-Glucosidase-albumin conjugates: effect of chronic administration in mice)
  • the polymer carrier is larger than the enzyme, where one or more enzyme molecules are immobilized on each molecule of the polymer. It is also possible that a single enzyme molecule will bind to more than one polymer molecule via two or more attachment sites.
  • the carrier may be natural, synthetic or semi- synthetic. Many such applications were developed in order to increase the in vivo stability of enzymes or to reduce immunogenicity.
  • One such family of polymers is cellulose ethers, including but not limited to carboxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, methyl cellulose and others.
  • Such immobilization has previously been accomplished with enzymes such as trypsin (Villaonga et al, 2000, Journal of Molecular Catalysis B: 10, 483-490 Enzymatic Preparation and functional properties of trypsin modified by carboxymethylcellulose) and lysozyme (Chen SH et al, 2003, Enzyme and Microbial Technology 33, 643-649, Reversible immobilization of lysozyme via coupling to reversibly soluble polymer), though such enzyme immobilization has never previously been used to affect mechanical properties of enzyme-crosslinked hydrogels or matrices.
  • enzymes such as trypsin (Villaonga et al, 2000, Journal of Molecular Catalysis B: 10, 483-490 Enzymatic Preparation and functional properties of trypsin modified by carboxymethylcellulose) and lysozyme (Chen SH et al, 2003, Enzyme and Microbial Technology 33, 643-649, Reversible immobilization of lysozyme via
  • GAG glycosaminoglycan
  • Enzymes can also be coupled to polysaccharides, such as dextran and starch derivatives such as hydroxyethyl starch. An example of this can be seen in example 13 where an enzyme was coupled to oxidized dextran.
  • covalent binding For example, by grafting biotin molecules on the surface of the enzyme (biotinylation) and immobilizing the biotinylated enzyme on avidin or streptavidin containing molecules or polymers.
  • the carrier may be a non crosslinkable soluble polymer whose function is to capture the crosslinking enzyme before or during the crosslinking reaction.
  • the capturing groups e.g. avidin or streptavidin may be grafted on the crosslinkable polymer itself, resulting in gradual immobilization of the crosslinking enzyme during the crossling reaction on the crosslinkable polymer. 5.
  • Non-covalent binding of the enzyme to a carrier or polymer For example, electrostatic interactions between the enzyme and the carrier or polymer may provide a stable but non-covalent bond when the net charge of the enzyme has an opposite sign to the net charge of the carrier.
  • Example 5 describes a comparison of enzyme-catalyzed gelation rate to enzyme activity values measured using a colorimetric assay. PEGylation is described in this Example as a non- limiting, illustrative method for increasing enzyme size.
  • PEGylation is the covalent attachment of polyethylene glycol (PEG) molecules to enzyme molecules and is a preferred method of increasing enzyme molecule size.
  • PEGylation The operation of adding such one or more PEG molecules is known as PEGylation.
  • PEG is a desirable material for use in increasing enzyme size as it is bio-inert and has also demonstrated the ability to limit the immunogenic response to PEGylated implanted or injected molecules. Although it is not known whether PEGylation of enzymes as described herein also causes such immunogenic masking (limited
  • One method of accomplishing enzyme PEGylation is by reacting the enzyme with activated metoxyl PEG (mPEG) that react with amine groups on the enzyme (amine PEGylation).
  • activated mPEG include succinimidyl (NHS) esters of mPEG (mPEG-succinate-NHS, mPEG- glutarate,-NHS, mPEG- valerate-NHS, mPEG- carbonate-NHS, mPEG- carboxymethyl-NHS, mPEG- propionate-NHS, mPEG- carboxypentyl-NHS), mPEG- nitrophenylcarbonate, mPEG-propylaldehyde, mPEG- Tosylate, mPEG-carbonylimidazole, mPEG-isocyanate, mPEG-epoxide.
  • NHS succinimidyl
  • the activated mPEGs can be those that react with thiol groups on the enzymes (thiol PEGylation).
  • the activated PEGs may be monofunctional, heterobifunctional or
  • the activated PEGs may be branched PEGs or multi-arm PEGs.
  • the size of the activated PEG may range from 1000 dalton to 40,000 dalton
  • the molar ratio of the activated PEG to lysine groups on the enzyme is from 0.1:1 to 100: 1 and preferably 0.5: 1 to 10: 1
  • the pH of the PEGylation reaction is 7-9. More preferably the pH of the reaction is 7.5 -8.5.
  • the PEGylated enzyme may be further purified from non-reacted enzyme or in order to reduce the size range of the PEGylation products.
  • the purification may be done using size-exclusion chromatography.
  • the purification may be done using ionic chromatography, such as SP-sephrose, Q-sepharose, SM-sepharose or DEAE-sepharose.
  • purification from non-reacted enzyme may also be done using dialysis, ultrafiltration or ammonium sulfate fractionation.
  • Example 1 describes PEGylation reaction of mTG with PEG-NHS (5kD). The size and distribution of
  • PEGylation products is dependent on the PEG to mTG ratio as well as the pH of the reaction.
  • Example 2 describes PEGylation reaction of mTG with PEG-NHS (5kD). The size and distribution of PEGylation products is dependent on the duration and pH of the reaction.
  • Example 3 describes PEGylation reaction of mTG with PEG-NHS (2kD). The size and distribution of PEGylation products is dependent on the PEG to mTG ratio.
  • Example 4 describes a TNBS assay for the determination of the PEGylation extent of various preparations of PEGylated mTG (5kD PEG). The results suggest that the extent of PEGylation depends on the activated PEG: mTG ratio in the reaction.
  • Example 5 describes assays for the determination of activity of PEGylated mTG. The results suggest that PEGylated mTG retains most its activity towards small substrates, such as hydroxylamine and CBZ-Gln-Gly but loses a significant portion of its activity towards larger substrates such as gelatin.
  • Example 8 describes the measurement of activity of mTG that has eluted from crosslinked gelatin gels. The results suggest that non-PEGylated mTG which is eluted from crosslinked gelatin gels retains most of its activity (86% of maximal calculated activity).
  • Example 9 describes the mechanical testing of gelatin gels crosslinked with PEGylated or non-PEGylated mTG. The results demonstrate that gelatin gels crosslinked with PEGylated mTG are stronger and considerably more flexible than gels cross-linked with non-PEGylated mTG.
  • Example 10 describes burst pressure testing of various gelatin sealant formulations. The results suggest that gelatin sealants made with PEGylated mTG demonstrate burst pressures results which are comparable to those of sealants made with non-PEGylated mTG.
  • Example 11 describes use of sealant for staple line reinforcement for in vivo porcine model.
  • Example 12 describes the effect of non-covalent binding of cross-linking enzyme to insoluble carrier.
  • Example 13 describes the effect of enzyme modification with oxidized dextran.
  • Example 14 demonstrates that modification of Horseradish Peroxidase (another crosslinking enzyme) by PEGylation can modify matrices formed by peroxidase cros slinking.
  • Example 15 demonstrates the effect of partial PEGylation of the cross-linking enzyme.
  • Example 16 demonstrates that free PEG (PEG molecule placed in solution with the crosslinking enzyme, but not covalently bound to the enzyme) has no effect on gelation.
  • Example 17 illustrates the effect of various mixtures of modified enzyme mixed with non-modified enzyme on gelation.
  • Example 18 demonstrates the effect of bi-functional PEG-enzyme bridges on gelation.
  • Example 19 relates to mass spectrometry analysis of PEGylated mTG (microbial transglutaminase).
  • Example 20 describes PEGylation of mTG at a fixed PEG to amine ratio with various concentrations of reactants, demonstrating the large effect of total reactant concentration on the extent of PEGylation.
  • TGases transglutaminases
  • these references teach the use of TGase as a tool for enabling or enhancing site specific PEGylation of other proteins (rather than as a substrate for PEGylation) by catalyzing the transglutamination reaction of glutamyl residues on the said proteins with a primary amine group attached to the said PEG molecules.
  • TGases transglutaminases themselves in order to alter or control their crosslinking activity or to alter or control the mechanical properties of hydrogel matrices crosslinked by these enzymes.
  • the enzyme undergoes a binding reaction to the crosslinked matrix itself simultaneous to catalyzing the crosslinking reaction.
  • the enzyme moves through the polymer solution to crosslink the polymers in a matrix, it is gradually bound to the polymers themselves and thus immobilized in the matrix.
  • biotinylated enzyme can be mixed with a crosslinkable polymer component containing avidin or streptavidin coated polymer.
  • US Patent 6046024 Method of producing a fibrin monomer using a biotinylated enzyme and immobilized avidin describes a method of capturing biotinylated thrombin from fibrinogen solution by adding avidin-modified agarose.
  • the agarose was not soluble, it is possible to bind avidin or streptavidin to water soluble polymer as well as described by United States Patent 5026785 (Avidin and streptavidin modified water-soluble polymers such as polyacrylamide, and the use thereof in the construction of soluble multivalent macromolecular conjugates). Biotinylation of transglutaminase and subsequent adsorption to avidin-treated surfaces has been shown to be feasible (Huang XL et al, J. Agric. Food Chem., 1995, 43 (4), pp 895-901). Alternatively, the
  • crosslinking enzyme may be covalently bound to avidin or streptavidin and the conjugate added to the crosslinking reaction which contains a biotinylated polymer.
  • biotinylated may be the crosslinkable polymer itself, e.g. gelatin, or a non-crosslinkable co-polymer such as dextran. Dextran-biotin conjugates of molecular weights of up to 500,000 dalton are available from commercial sources. Reduced Mobility of Crosslinking Enzyme by Electrostatic Interactions in Crosslinked Matrix
  • enzyme mobility is reduced through reversible binding based on electrostatic interactions between the enzyme and a polymer carrier in which the net charge of the enzyme has an opposite sign to the net charge of the carrier.
  • the enzyme may be pre-incubated with the carrier and added to the crosslinking reaction or it may be bound to the carrier during the cross linking reaction.
  • a negatively charged carrier for example carboxymethyl cellulose (CMC).
  • CMC carboxymethyl cellulose
  • the enzyme may be incubated with CMC to allow binding and then the complex added to the crosslinking reaction, or the enzyme and CMC are added separately . In the latter case the enzyme will bind the CMC gradually during the crosslinking reaction.
  • the enzyme it is also possible to bind the enzyme to the crosslinkable polymer strands themselves during the crosslinking reaction, provided that the crosslinkable polymer bears an opposite sign charge relative to the crosslinking enzyme.
  • the isoelectric point (pi) of the crosslinking enzyme can be shifted such that the enzyme acquires an opposite sign charge than that of the crosslinkable polymer or carrier.
  • the crosslinking enzyme is modified in such a way that its isoelectric point (pi) is changed to result in a different net charge on the enzyme at a given pH.
  • ways to reduce the pi of the enzyme are to modify the ⁇ -amino group of lysines by processes such as but not limited to succinylation (with succinic anhydride), acetylation (with acetic anhydride), carbamylation (with cyanate), reductive alkylation (aldehydes) and treatment with maleic anhydride. This results in decrease in the positive net charge on the protein by up to one charge unit per modified amino acid (except for succinylation which decreases the positive net charge by up to two charge units) and decrease in the pi.
  • side chains containing carboxylic acids such as glutamic and aspartic acid may be modified in order to decrease the number of negative charges on the protein and as a result increase the pi.
  • carboxylic acids such as glutamic and aspartic acid
  • EDC activates the carboxylic acid groups and an amide bond is formed between them and EDA. The result is an increase in the positive net charge of the protein and in the pi.
  • the background art involved manipulating electrostatic interactions between proteins entrapped within a hydrogel and the hydrogel chains are concerned with methods of controlling the release rate of the therapeutic proteins from the hydrogel, where the proteins are not themselves involved in the formation of the hydrogel.
  • the electrostatic interactions are modified to improve the hydrogel mechanical properties, which may be related to mobility and diffusion coefficient of the enzyme in the hydrogel matrix that the enzyme is crosslinking.
  • Changing the pi of the entrapped crosslinking enzyme is therefore a novel approach to prevent over cross linking because the diffusion or mobility of the cross linking enzyme in the cross linkable matrix is severely restricted by modification of the pi of the entrapped enzyme rather than of the polymeric hydrogel.
  • Example I Effect of reaction pH, and PEG: mTG ratio on size and distribution of PEGylation products
  • Activated PEG mPEG-glutarate-NHS 5kDa (SunBright ME-050GS, NOF corporation, Japan)
  • mTG Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography.
  • Activity 604 units/ml in 0.2M sodium citrate pH 6
  • sodium citrate, Hepes , SDS and beta mercaptoethanol were from Sigma Aldrich.
  • the reactions were incubated at 37°C for 1:36 hr and then glycine was added to a final concentration of l lOmM in order to neutralize the excess of activated PEG molecules that have not reacted with the enzyme.
  • Lane 1 mTG (control)
  • Lane 2 Molecular size marker (from top to bottom: 250kD, 150 kD, lOOkD, 75 kD, 50kD, 37kD, 25kD)
  • Lane 3 53.3 mg/ml activated PEG; 90mM Na citrate pH 6; PEG to lysine ratio 9.15
  • Lane 4 26.6 mg/ml activated PEG; 90mM Na citrate pH 6; PEG to lysine ratio 4.59
  • Lane 5 13.3 mg/ml activated PEG; 90mM Na citrate pH 6; PEG to lysine ratio 2.30
  • Lane 6 53.3 mg/ml activated PEG; lOOmM Hepes pH 7; PEG to lysine ratio 9.15 Lane 7: 26.6 mg/ml activated PEG; lOOmM Hepes pH 7; PEG to lysine ratio 4.59
  • Lane 8 13.3 mg/ml activated PEG; lOOmM Hepes pH 7 PEG to lysine ratio 2.30
  • Activated PEG mPEG-glutarate-NHS 5kDa (SunBright ME-050GS, NOF corporation, Japan)
  • mTG Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography.
  • Activity 604 units/ml in 0.2M sodium citrate pH 6
  • sodium citrate, Hepes , SDS and beta mercaptoethanol were from Sigma Aldrich.
  • a set of reactions was set up, each with a volume of 0.2 ml, All reactions contained 15 u/ml mTG, the approprtiate reaction buffer- either 100 mM Hepes, pH 7 or lOOmM Hepes pH 8, and 25 mg/ml PEG-NHS.
  • the ratio of PEG to lysine residues in the reaction mix was 4.59.
  • Lane 1 25 mg/ml activated PEG; lOOmM Hepes pH 8; 15 min reaction time
  • Lane 2 25 mg/ml activated PEG; lOOmM Hepes pH 8; 30 min reaction time
  • Lane 3 25 mg/ml activated PEG; lOOmM Hepes pH 8; 60 min reaction time
  • Lane 4 25 mg/ml activated PEG; lOOmM Hepes pH 8; 120 min reaction time
  • Lane 5 Molecular size marker (from top to bottom: 250kD, 150 kD, lOOkD, 75 kD, 50kD, 37kD, 25kD)
  • Lane 6 25 mg/ml activated PEG; lOOmM Hepes pH 7; 15 min reaction time
  • Lane 7 25 mg/ml activated PEG; lOOmM Hepes pH 7; 30 min reaction time
  • Lane 8 25 mg/ml activated PEG; lOOmM Hepes pH 7; 60 min reaction time
  • Lane 9 25 mg/ml activated PEG; lOOmM Hepes pH 7; 120 min reaction time
  • Example 3 PEGylation of mTG with PEG-NHS (2kD): effect of PEG: mTG ratio on size and distribution of PEGylation products
  • Activated PEG mPEG-glutarate-NHS 2kDa (SunBright ME-020CS, NOF corporation, Japan)
  • mTG Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography.
  • Activity 604 units/ml in 0.2M sodium citrate pH 6
  • sodium citrate, Hepes , SDS and beta mercaptoethanol were from Sigma Aldrich.
  • 1 unit of mTG activity will catalyze the formation of 1.0 ⁇ of hydroxamate per min from N-CBZ-Gln-Gly and hydroxylamine at pH 6.0 at 37°C.
  • Reactions 200 ⁇ contained 15 u/ml mTG, lOOmM Hepes, pH 8 and various concentrations of PEG NHS (2kD). The reactions were incubated at 37 °C for 2 hours, followed by addition of ⁇ 1.5 M glycine (71mM final concentration) in order to neutralize the PEG-NHS molecules that have not reacted with the enzyme.
  • Lane 2 1.75 mg/ml PEG-NHS 2kD; PEG to lysine ratio 0.74
  • Lane 3 3.5 mg/ml; PEG-NHS 2kD; PEG to lysine ratio 1.48
  • Lane 4 7 mg/ml; PEG-NHS 2kD ; PEG to lysine ratio 2.97
  • Lane 5 14 mg/ml;; PEG-NHS 2kD ; PEG to lysine ratio 5.93
  • Lane 6 28 mg/ml; PEG-NHS 2kD ; PEG to lysine ratio 11.86
  • Lane 7 56 mg/ml; PEG-NHS 2kD ; PEG to lysine ratio 23.72
  • Example 4 TNBS assay for determining extent of PEGylation
  • Glycine and 5% TNBS solution were from Sigma Aldrich
  • Dilute TNBS solution was prepared by mixing 5% TNBS 1 in 500 in bicarbonate buffer (pH 8.5)
  • the spectrophotometer was Anthelie Advanced (Secomam)
  • 0.5ml of diluted TNBS solution was mixed with 1 ml of standard glycine solution or sample. The mixture was incubated at 37°C for 2 hours. Next, 0.5 ml of 10% SDS solution and 0.25ml of 1M HCL were added to stop the reaction. The solutions were transferred to a cuvette and the O.D. was read at 335nm using a spectrophotometer.
  • the percentage of free NH 2 groups was determined for each PEGylated mTG based on the calibration curve set up for glycine.
  • Gelatin (Pig skin Type A 275 bloom) was from Gelita
  • the PEGylation reaction (8 ml) contained 15 u/ml mTG, lOOmM HEPES (pH 7) and 14 mg/ml PEG-NHS (5kD).
  • the reaction conditions were similar to those in lane 8 in Fig. 1.
  • the reaction incubated at 37°C for 1:50 hours, followed by addition of 0.4 ml 2.34 M glycine (lOOmM final concentration) in order to neutralize the non-reacted activated PEG.
  • the concentrated PEGylated mTG is referred to as 4X, while 2-fold and 4-fold dilutions of it in citrate buffer are referred to as 2X and IX, respectively.
  • gelation time is the time at which the liquid stops flowing when the reaction tube in inverted.
  • reaction cocktail 1 mL was added to each of reaction A-D and the mix was incubated at 37°C for 10 minutes or 20 minutes. At each time point, 0.23 ml of the reaction was added to a tube with 0.5 mL TCA and 0.5 mL.
  • Example 6 elution profile of PEGylated and non-PEGylated mTG from gels of gelatin
  • Gelatin (Pig skin type A, 275 bloom) was from Gelita
  • a crosslinked gelatin gel was made by mixing 0.67 ml of an enzyme mix comprising of 1:1 mixture of PEGylated mTG (The reaction conditions were similar to those in lane 6 in Fig. 1) and 20 u/ml mTG with 1.33 ml of gelatin solution (25% gelatin, 3.8M urea, 0.15M CaCl 2 , 0.1M Na acetate pH 6). The resulting gel was wrapped in saran wrap and incubated at 37 °C for 2 hours.
  • the gel was placed in a tube containing 10 ml saline and was incubated for 4 hours at 37°C shaker incubator. Samples were taken every hour. Samples were concentrated using Amicon Ultra-4 Centrifugal Filter Unit MWCO 30,000 (Millipore), denatured by heating at 90°C in the presence of SDS and beta mercaptoethanol and were analyzed using SDS-PAGE (8% resolving gel, 4% stacking gel, Mini-Protean electrophoresis system, BioRad). To visualize the proteins the gel was stained with Bio-Safe Coomassie G-250 stain followed by destaining with water.
  • Lane 5 Molecular size marker Lane 6: 7 ⁇ mTG+ PEGylated mTG mix
  • Lane 8 1.5 ⁇ mTG+ PEGylated mTG mixture
  • Figure 4 shows elution of mTG and PEGylated mTG from the same crosslinked gelatin gel.
  • Table 3 shows the relative amounts of transglutaminase eluted from the gel.
  • mPEG-glutaryl-NHS MW 5000 (SunBright ME-050GS, NOF corporation, Japan)
  • mPEG-succinyl-NHS MW 2000 (SunBright ME-020CS, NOF corporation, Japan)
  • mTG Ajinimoto active 10% further purified using SP-sepharose ion exchange chromatography.
  • the PEGylation reaction (32 ml) contained 15 u/ml mTG, lOOmM HEPES (pH 8) and various concentrations of PEG-NHS (2kD or 5kD).
  • the reactions were incubated at room temperature for 2.5 hours, followed by addition of 2.2 ml 1.5 M glycine (97mM final concentration) in order to neutralize the non-reacted activated PEG. After 15 minutes of further incubation at room temperature the reaction mix was concentrated down to 8 ml using Vivaspin 20 (Sartorius) while at the same time the reaction buffer was changed to 0.2 M Na citrate pH 6.
  • Samples from each timepoint were denatured by heating at 90°C in the presence of SDS and beta mercaptoethanol and were analyzed using SDS-PAGE (8% resolving gel, 4% stacking gel, Mini-Protean electrophoresis system, BioRad). To visualize the proteins the gel was stained with Bio-Safe Coomassie G-250 stain followed by destaining with water. In order to quantitate the intensities of the bands in SDS-PAGE, the gel was scanned with CanoScan 8800F scanner and the resulting image, shown in Figure 5, was analyzed using Quantity One software (Bio-Rad).
  • the maximal theoretical amount of enzyme that would have been released was loaded on the SDS-PAGE as well and was taken as 100% release.
  • the actual elution samples were ran side by side and the intensities of the bands were calculated relative to the 100% release.
  • the gel was scanned with CanoScan 8800F scanner and the resulting image was analyzed using Quantity One software (Bio-Rad).
  • Figure 5 shows elution of mTG (left) and PEGylated mTG (right) from different crosslinked gelatin gels.
  • the lane assignments are given below.
  • Lane 2 mTG released from crosslinked gelatin gel, lhr time -point
  • Lane 3 mTG released from crosslinked gelatin gel, 2hr time-point
  • Lane 4 mTG released from crosslinked gelatin gel, 3hr time-point
  • Lane 5 mTG released from crosslinked gelatin gel, 18hr time-point
  • Lane 7 PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, lhr time-point
  • Lane 8 PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, 2hr time-point
  • Lane 9 PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, 3hr time-point
  • Lane 10 PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, 18hr time-point
  • Table 4 % elution from gelatin gels of different types of PEGylated mTG.
  • the measured activity was found to be 3.65 u/ml.
  • the calculated activity (based on initial activity in the gel of 5 u/ml and % release at 18 hr according to SDS-PAGE in Fig. 5 and its quantitation in Table 4 of 26.7%) is 4.24 u/ml.
  • Example 9 mechanical testing of gelatin gels crosslinked with PEGylated or non- PEGylated mTG.
  • Gelatin (Pig skin Type A 275 bloom) was from Gelita.
  • mTG was from Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography.
  • Activity 604 units/ml in 0.2M sodium citrate pH 6.
  • PEGylated mTG (either 2kD or 5kD PEG-NHS) with various degrees of PEGylation was prepared as described in Example 7.
  • 1 part of PEGylated mTG solution was mixed with 2 parts of gelatin solution (25% gelatin, 3.8M urea, 0.15M CaCl 2 , 0.1M Na acetate pH 6).
  • the mixture was poured into a Teflon-coated dog bone shaped mold. After gelation occurred, the gels were taken out of the molds, submerged in saline and incubated at 37°C for 4 hours. The dimensions of the dogbone- shaped gel were then measured using a digital caliper. Control samples were made using 1 part of 15u/ml of non-PEGylated mTG and 2 parts of gelatin solution. For both types of samples, the following testing protocol was followed:
  • the sample was clamped into a tensile testing system (Instron model 3343) such that the gel sample between the clamps was approximately 12 (width) x 1.9 (thickness) x 20 (length) mm.
  • the precise dimensions of each sample were measured immediately prior to tensile testing and these measured values were used to calculate the material properties of the samples.
  • tension was applied to each sample at a rate of 0.25 mm/s until a pre-load of 0.025 N was achieved. This was considered the 0% strain point.
  • tensile strain was continuously applied to the sample at a rate of 0.5 mm/s until the sample failed by fracture.
  • Table 5 shows the mechanical testing of various types of PEGylated mTG.
  • the left most column refers to the conditions of PEGylation, given as A-B; the value of A as 7 refers to 7 mg/ml PEG, the value of A as 14 refers to 14 mg/ml PEG, and the value of A as 28 refers to 28 mg/ml PEG; the value of B as 2 refers to 2 kD PEG, while the value of B as 5 refers to 5 kD PEG.
  • increased amounts of PEG result in increased gelation time and reduced Young's modulus; however, increased PEG size results in increased tensile strength and increased flexibility of the resultant gel .
  • Example 10 Performance of sealant on living tissue using the burst pressure test.
  • Porcine small intestine tissues were cleaned of residual material and cut into 10 cm pieces. In each piece a 14 gauge needle puncture was made. The tissues were then be soaked in a saline solution and incubated at 37°C. Prior to applying the sealant material, which was prepared as described in Example 7, the tissue was flattened and the application site of each tissue was blotted using a gauze pad. Approximately 0.1-0.2 mL of tested sealant was applied on each application site using a 1 mL syringe. Within 5min of the application the tissue was washed with saline and incubated at 37°C, for 4 hours. Each test group was examined in triplicates or more.
  • the tissue were placed in the Perspex Box, one side tightly sealed (using a clamp) and the other connected to the pressure meter and hand pump (using a plastic restraint).
  • the Perspex box was filled with saline so that tissue sample is totally submerged. Air was pumped, using the hand-pump at a constant rate (20 mL/min). Burst pressure was determined by the appearance of bubbles.
  • a Covidien EEA circular surgical stapler was used to perform a circular anastomosis in the rectum of a pig.
  • Surgical sealant comprised of gelatin solution and PEGylated TG was prepared as in example 7, with 28 mg/ml 5 kDa PEG-NHS in a reaction volume of 72 ml.
  • the reaction mix was concentrated using Viva-Spin 20 MWCO 30,000 (Sartorius) to 3 ml, such that the activity of the concentrated PEGylated enzyme was equivalent to 40 u/ml of non-PEGylated enzyme.
  • 4 mL of sealant (comprised of 2.66 ml gelatin solution and 1.33 PEGylated enzyme solution) was applied evenly around the circumference of the rectal staple-line and left to cure for 4 minutes. The animal was then closed.
  • the sealant did not undergo significant degradation over the course of the 14 day implantation period. It remained strongly adhered to the staple line, maintaining 100% integrity over the length of the staple line.
  • the sealant material was pliable and flexible, matching the shape and movement of the circular staple-line shape.
  • Example 12 Non-covalent binding of cross-linking enzyme to insoluble carrier
  • SP sepharose was bound to mTG (microbial transglutaminase) and a gel was made. Gelation occurred in 16-23 minutes with immobilized transglutaminase, while soluble enzyme caused gelation to occur in less than 6 minutes. Immobilization therefore increased the time required for gelation.
  • the mTG-loaded beads were mixed with 50mM NaAc pH 5.5 in various compositions in a final volume of 600 ⁇ as follows (in parenthesis the amount of bound mTG and the calculated theoretical mTG activity based on the measured activity of 1 mg unbound mTG - 33 hydroxamate units):
  • the reaction was dialyzed 3 times against 1L PuW for 2:00 hr, with water change in between.
  • Figure 7 shows SDS-PAGE analysis of conjugation reactions A-D.
  • the following amounts of dextran- conjugated mTG were loaded on a 4-15% Mini-Protean TGX gel (Bio-Rad): 4.35 ⁇ g (Reaction A), 4.38 ⁇ g (Reaction B), 1.98 ⁇ g (Reaction C) and 3 ⁇ g (Reaction D).
  • the samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading.
  • the gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio- Rad).
  • the molecular weight marker was Precision Plus (Bio-Rad).
  • the example shows that it is possible to immobilize a crosslinking enzyme, in this case mTG (microbial transglutaminase), on a soluble polymer. Furthermore, at higher dextran:mTG ratios, more molecules of free mTG are converted to high MW conjugates with dextran.
  • mTG microbial transglutaminase
  • the crosslinking enzyme is horseradish peroxidase (HRP) and HRP is modified by attachment of PEG molecules to the HRP molecules in order to modify the mechanical properties of the gelatin hydrogel formed by HRP crosslinking.
  • HRP horseradish peroxidase
  • phenol-modified gelatin (gelatin-Ph): Two grams of high molecular weight gelatin Type A were dissolved in 100 ml 50mM MES (2-(N- morpholino)ethanesulfonic acid; Sigma Aldrich) buffer pH 6. To this 2% w/w solution the following reagents were added: 0.984 gram tyramine (Sigma Aldrich). 0.218 gram NHS (N-Hydroxysuccinimide; Sigma Aldrich), 0.72 gram EDC (l-Ethyl-3-[3- dimethylaminopropyl]carbodiimide; Sigma Aldrich).
  • HRP and PEGylated HRP dependent gelation of gelatin-Ph Gelatin component: 5ml gelatin-Ph + 0.5ml 20mM H 2 0 2 mixed in a glass vial : 4.4 ml were transferred to syringe A.
  • HRP/PEGylated HRP component 1ml 0.035mg/ml HRPor PEGylated HRP in Syringe B.
  • the gelatin and enzyme components were mixed by syringe to syringe transfer and then incubated at 37°C while being inverted to determine gelation time.
  • Cross-linking enzyme with pegylation to different degrees resulted in different degrees of mechanical properties.
  • This example demonstrates how the mechanical properties of a enzymatically crosslinked hydrogel can be specifically controlled by modulating the hydrodynamic volume, in this case the degree of PEGylation, such that greater hydrodynamic volume (i.e. more PEGylation) results in a more elastic matrix and less hydrodynamic volume (i.e. less PEGylation results in a less elastic matrix.
  • the unmodified hydrodynamic volume i.e. no PEGylation results in the least elastic matrix.
  • Instron data and SDS-Page gel data are described below with regard to these effects.
  • PEGylation reactions were performed side by side. The reactions were done at room temperature for 2.5 hr in lOOmM HEPES pH 8.0 using PEG-NHS 5K . Following the reaction, the unreacted excess PEG was neutralized with l lOmM glycine and incubation continued for 30 more minutes.
  • Reaction A and B had the same PEG:amine ratio but in A, both the mTG and the PEG were 3x more concentrated than in B.
  • Reaction C is similar to A but the PEG:amine ratio was half the ratio in A. The results are shown in Table 8.
  • PEG cone (mg/ml) 21.00 7.00 10.50
  • each resulting solution of PEGylated mTG solution was reacted with a 25% gelatin solution (in sodium acetate buffer with 4.5M urea) at a 1 :2 ratio, mTG solution to gelatin solution, to form a gelatin hydrogel.
  • the mTG activity levels of each PEGylated mTG solution were normalized such that the reaction time with the gelatin was identical for all groups. Following the formation of each hydrogel, it was cultured at 37 °C for 2 hours and then mechanically tested using a tensile testing system.
  • Results are shown in Figure 9, which is an image of SDS-PAGE analysis of PEGylated mTG.
  • PEGylated mTG from reactions A, B and C (5 ⁇ g of each) were loaded on a 6% polyacrylamide gel and subjected to SDS-PAGE.
  • the samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading.
  • the gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio-Rad).
  • the molecular weight marker was Precision Plus (Bio-Rad).
  • the SDS-PAGE profile shows how reactions A, B, and C resulted in mTG molecules bound with PEG molecules to different degrees such that many PEG molecules are bound to the mTG in A, fewer in B, and even fewer in C.
  • PEGylation of the enzyme molecules results in a significant increase in matrix elasticity, as can be seen in several other examples.
  • Example 17 Mixed modified/non-modified cross-linking enzyme
  • modified enzyme is used together with unmodified (free) enzyme in order to achieve mechanical modification of an enzyme-crosslinked matrix.
  • This experiment demonstrated cross-linking of enzyme to itself through a bi- functional PEG bridge.
  • two or more enzyme molecules can be bound to each other to increase the overall hydrodynamic volume of the enzyme aggregate.
  • One way of accomplishing this is by using a bi-functional molecule that forms a bridge between enzyme molecules.
  • each reaction composition was loaded on a 7.5% polyacrylamide gel and subjected to SDS-PAGE analysis.
  • the samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading.
  • the gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio-Rad).
  • the molecular weight marker was Precision Plus (Bio-Rad).
  • Intact molecular mass measurement was performed on a Bruker Reflex III matrix- assisted laser desorption /ionization (MALDI) time-of-flight (TOF) mass spectrometer (Bruker, Bremen, Germany) equipped with delayed ion extraction, reflector and a 337 nm nitrogen laser. Each mass spectrum was generated from accumulated data of 200 laser shots. External calibration for proteins was achieved by using BSA and myoglobin proteins (Sigma, St Louis, MO).
  • MALDI matrix- assisted laser desorption /ionization
  • TOF time-of-flight
  • DAB 2,5-Dihydroxybenzoic acid
  • TFA TriFluoro Acetic acid
  • ACN acetonitrile
  • Example 20 PEGylation of mTG at a fixed PEG to amine ratio with various concentrations of reactants. This example demonstrates the large effect of total reactant concentration on the extent of PEGylation. When the ratio of PEG:amine was maintained at a fixed value, a correlation between the concentration of reactants (PEG and mTG) and the extent of PEGylation was demonstrated.
  • PEGylation of mTG with PEG-NHS-5kD was carried out at room temperature in lOOmM Hepes pH 8.0 for 2.5 hours, followed by addition of l lOmM glycine to neutralize unreacted PEG-NHS.
  • 5 ⁇ g of enzyme each reaction composition was loaded on a 6.0% polyacrylamide gel and subjected to SDS-PAGE analysis.
  • the samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading.
  • the gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio-Rad).
  • the molecular weight marker was Precision Plus (Bio-Rad).

Abstract

Improved matrix or hydrogel that is formed by enzymatic crosslinking of polymers wherein the crosslinking enzyme molecules have been modified for the purpose of improving the crosslinking density, mechanical properties, or other properties of the matrix, and/or to provide improved control over the rate and/or extent of crosslinking, wherein the enzyme molecules are modified to alter the perceived volume of the enzyme molecules in the crosslinked matrix being formed. Methods of production and of use are also provided.

Description

Title: Modification of enzymatic crosslinkers for controlling properties of crosslinked matrices
Inventors: Guy Tomer and Orahn Preiss-Bloom BACKGROUND
Utility of Enzyme Crosslinked Matrices
Enzyme crosslinked matrices are formed in a variety of applications in the food, cosmetic, and medical industries. In medical applications in particular, enzyme crosslinked hydrogels are widely used in a variety of medical applications including tissue sealants and adhesives, haemostatic preparations, matrices for tissue engineering or platforms for drug delivery. While some hydrogels such as gelatin and poloxamer may be formed as a result of physical interactions between the polymer chains under specific conditions, e.g change in temperature, most polymer solutions must be crosslinked in order to form hydrogels. In addition to the actual formation of the solid gel, implantable hydrogels must be resistant to the conditions that are prevalent in the tissue where they are applied, such as mechanical stress, temperature increase, and enzymatic and chemical degradation. For this reason, in many cases it is necessary to crosslink the hydrogel matrices. The crosslinking may be done outside the body by pre-casting or molding of hydrogels. This application is used mainly for tissue engineering or drug delivery applications. Alternatively, crosslinking may be done inside the body (in situ gelation or cross linking) where a liquid solution is injected or applied to the desired site and is cross linked to form a gel.
Gel formation can be initiated by a variety of crosslinking approaches. Chemical approaches to gel formation include the initiation of polymerization either by contact, as in cyanoacrylates, or external stimuli such as photo-initiation. Also, gel formation can be achieved by chemically crosslinking pre-formed polymers using either low molecular weight crosslinkers such as glutaraldehyde or carbodiimide (Otani Y, Tabata Y, Ikada Y. Ann Thorac Surg 1999, 67, 922-6. Sung HW, Huang DM, Chang WH, Huang RN, Hsu JC. J Biomed Mater Res 1999, 46, 520-30. Otani, Y.; Tabata, Y.; Ikada, Y. Biomaterials 1998, 19, 2167-73. Lim, D. W.; Nettles, D. L.; Setton, L. A.; Chilkoti, A. Biomacromolecules 2008, 9, 222-30.), or activated substituents on the polymer (Iwata, H.; Matsuda, S.; Mitsuhashi, K.; Itoh, E.; Ikada, Y. Biomaterials 1998, 19, 1869-76). However, chemical crosslinking can be problematic in food, cosmetic, or medical applications because the cross-linkers are often toxic, carcinogenic, or irritants.
Furthermore, they are small molecules that can readily diffuse out of the crosslinked matrix and might cause local or systemic damage.
An alternative to chemical crosslinking is the enzymatic crosslinking approach.
These approaches to initiate gel formation have been investigated based on a variety of different crosslinking enzymes. Examples include enzymatic crosslinking of adhesives, such as mussel glue (Strausberg RL, Link RP. Trends Biotechnol 1990, 8, 53-7), or the enzymatic crosslinking of blood coagulation, as in fibrin sealants (Jackson MR. Am J Surg 2001, 182, 1S-7S. Spotnitz WD. Am J Surg 2001, 182, 8S-14S Buchta C, Hedrich HC, Macher M, Hocker P, Redl H. Biomaterials 2005, 26, 6233-41.27-30).
Cross-linking of a mussel glue was initiated by the enzymatic conversion of phenolic (i.e., dopa) residues of the adhesive protein into reactive quinone residues that can undergo subsequent inter-protein crosslinking reactions (Burzio LA, Waite JH. Biochemistry 2000, 39, 11147-53. McDowell LM, Burzio LA, Waite JH, Schaefer JJ. Biol Chem 1999, 274,20293-5). The enzymes which have been employed in this class of sealants are tyrosinase on one hand and laccase and peroxidase on the other hand which acts by forming quinones and free radicals, respectively from tyrosine and other phenolic compounds. These in turn can crosslink to free amines on proteins or to similarly modified phenolic groups on proteins and polysaccharides.
A second cross-linking operation that has served as a technological model is the transglutaminase-catalyzed reactions that occur during blood coagulation (Ehrbar M, Rizzi SC, Hlushchuk R, Djonov V, Zisch AH, Hubbell JA, Weber FE, Lutolf MP. Biomaterials 2007, 28, 3856-66). Biomimetic approaches for in situ gel formation have investigated the use of Factor XUIa or other tissue transglutaminases (Sperinde J, Griffith L. Macromolecules 2000, 33, 5476-5480. Sanborn TJ, Messersmith PB, Barron AE. Biomaterials 2002, 23, 2703-10).
An additional in situ crosslinked gel formation of particular interest is the crosslinking of gelatin by a calcium independent microbial transglutaminase (mTG). mTG catalyzes an analogous crosslinking reaction as Factor XUIa but the microbial enzyme requires neither thrombin nor calcium for activity. Initial studies with mTG were targeted to applications in the food industry (Babin H, Dickinson E. Food Hydrocolloids 2001, 15, 271-276. Motoki M, Seguro K. Trends in Food Science & Technology 1998, 9, 204-210.), while later studies considered potential medical applications. Previous in vitro studies have shown that mTG can crosslink gelatin to form a gel within minutes, the gelatin-mTG adhesive can bond with moist or wet tissue, and the adhesive strength is comparable to, or better than, fibrin-based sealants (Chen TH, Payne GF, et al. Biomaterials 2003, 24, 2831-2841. McDermott MK, Payne GF, et al. Biomacromolecules 2004, 5, 1270-1279. Chen T, Payne GF, et al. J Biomed Mater Res B Appl Biomater 2006, 77, 416-22.). The use of gelatin and mTG as a medical adhesive is described in PCT WO/2008/076407.
One of the disadvantages of using enzymes as the cross-linkers in crosslinked matrix formation is that they may continue the cross linking reaction after the desired gel state has been formed. This is often not desired because excessive cross linking may result in a stiffer, more brittle, and less flexible gel. In addition, the mechanical properties of the crosslinked matrix will continue to change during the lifetime of the gel, making consistent properties difficult to achieve. The continued enzymatic cross linking beyond the desired crosslinking density results from the ability of the enzyme to continue to catalyze the crosslinking reaction even once a crosslinked matrix or hydrogel has been formed. This depends on the ability of the enzyme to continue to diffuse throughout the matrix even as solution viscosity increases greatly. This view is consistent with Hu et al (Hu BH, Messersmith PB. J. Am. Chem. Soc, 2003, 125 (47), pp 14298-14299) who suggested, based on work done with peptide-grafted synthetic polymer solutions, that during incipient network formation resulting from partial cross-linking of a polymer solution, the solution viscosity rapidly increases while the mobility of the
transglutaminase rapidly decreases.
The problem of excessive enzymatic crosslinking leading to a reduction in mechanical properties has been previously documented on several occasions:
Bauer et al. demonstrated that high levels of microbial transglutaminase (mTG) caused excessive cross-linking of wheat gluten proteins leading to a loss of elasticity and mechanical damage of the gluten networks. (Bauer N, Koehler P, Wieser H, and
Schieberle P. Studies on Effects of Microbial Transglutaminase on Gluten Proteins of Wheat II Rheological Properties. Cereal Chem. 80(6):787-790).
Sakai et al. found that a larger quantity of covalent cross-linking between phenols was effective for enhancement of the mechanical stability, however, further cross-linking between the phenols resulted in the formation of a brittle gel. (Sakai S, Kawakami K. Synthesis and characterization of both ionically and enzymatically crosslinkable alginate, Acta Biomater 3 (2007), pp. 495-501)
In the case of cofactor-dependent crosslinking enzymes, such as calcium- dependent transglutaminase, removing the cofactor, by binding or otherwise, after a certain reaction time can limit the degree of crosslinking. However, cofactor removal is frequently not technically feasible in hydrogel formation where the hydrogel may trap the cofactor. When using cofactor-independent enzymes, such as transglutaminases available from microbial origin, limited degrees of crosslinking can be obtained by heat treatment of the reaction system. However, such a treatment induces negative side effects on protein functionality and is therefore undesirable to apply. In addition, not all reaction systems are suitable to undergo heat treatment.
Other than resulting in excessive crosslinking within the crosslinked matrix, continued diffusion of the crosslinked enzyme in the matrix after the desired crosslinked state has been achieved also can result in a high rate of enzyme diffusion out of the gel, also known as enzyme elution. This can also be problematic as high levels of
crosslinking enzyme released into the body can interact with body tissues and cause local or systemic damage.
SUMMARY OF INVENTION
There is a need for, and it would be useful to have, an improved enzyme
crosslinked composition which could be used for a wide variety of applications.
Therefore, there is a need for, and it would be useful to have a mechanism to stop enzymatic cross linking of crosslinked matrices following the initial formation of the solid matrix at a point where the desired mechanical properties have obtained; and/or to reduce the extent and rate of elution of the enzyme from the solid crosslinked matrix.
The present invention, in at least some embodiments, overcomes the above described drawbacks of the background art, and provides a solution to the above technical problems (among its many advantages and without wishing to provide a closed list), by providing a matrix or hydrogel that is formed by enzymatic crosslinking of polymers wherein the crosslinking enzyme molecules have been modified for the purpose of improving the crosslinking density, mechanical properties, or other properties of the matrix, and/or to provide improved control over the rate and/or extent of crosslinking. An optional method of altering the enzyme molecules is by modifying the perceived volume of the enzyme molecules in the crosslinked matrix being formed. The modified perceived volume is preferably determined according to the extent of crosslinking of the polymers to form the matrix, such that decreased extent of
crosslinking, as compared with extent of crosslinking with unmodified enzyme molecules, indicates increased perceived volume.
One method of increasing the perceived volume of the enzyme molecules is by increasing the size and/or the hydrodynamic volume of the molecules by covalent or non- covalent attachment of at least one molecule or moiety to the enzyme molecules. The inventors have demonstrated that the degree of enzymatic crosslinking in hydrogels or crosslinked matrices can be regulated by covalent attachment of molecules to the enzyme such that the modification of the enzyme molecules result in a lower ultimate level of crosslinking. In this manner, the phenomenon of excessive crosslinking can be prevented.
Another method of increasing the perceived volume is through modification of the electrostatic charge of the enzyme molecules such that their net charge is of opposite sign to the net charge on the polymer or co-polymer chains. This can be achieved by changing the isoelectric point (pi) of the enzyme.
In a non-limiting hypothesis, increasing the perceived volume of the enzyme molecules reduces the mobility or diffusion of the molecules in the crosslinked matrix or hydrogel. This prevents it from continuing its crosslinking activity beyond the point where the crosslinking is beneficial to the desired material properties of the hydrogel.
"Perceived volume" or "effective volume" as defined herein refers to the effective hydrodynamic volume of the crosslinking enzyme inside the crosslinked matrix. The perceived volume may be increased by covalent or non-covalent binding of the enzyme to another molecule, carrier, polymer, protein, polysaccharide and others, prior to the crosslinking reaction or during the crosslinking reaction.
"Diffusion" or "Mobility" as defined herein refers to the random molecular motion of the crosslinking enzyme or other proteins, in solution, hydrogen, or matrix that result from Brownian motion.
"Diffusion coefficient" as defined herein refers to a term that quantifies the extent of diffusion for a single type of molecule under specific conditions. A non-limiting example of a proxy for measuring enzyme diffusion is by measuring the elution of enzyme from a hydrogel.
"Reduced Mobility" as defined herein refers to a slower molecular motion or smaller diffusion coefficient of a protein or enzyme in a solution or inside a hydrogel.
"Size" as defined herein refers to the molecular weight or hydrodynamic volume or perceived volume of a molecule.
"Molecular weight", abbreviated as MW, as used herein refers to the absolute weight in Daltons or kilodaltons of proteins or polymers. For example, the MW of a PEGylated protein (ie - protein to which one or more PEG (polyethylene glycol) molecules have been coupled) is the MW sum of all of its constituents.
"Hydrodynamic Volume" as defined herein refers to the apparent molecular weight of a protein or enzyme that may usually be measured using size exclusion chromatography. The hydrodynamic volume of a constituent refers to the diameter or volume the constituent assumes when it is in motion in a liquid form.
"Matrix" as defined herein refers to refers to a composition of crosslinked materials. Generally, when the matrix-forming materials are crosslinked, the composition that includes these materials transitions from a liquid state to a gel state, thereby forming a "gel," "hydrogel" or a "gelled composition." The gel can have certain viscoelastic and rheological properties that provide it with certain degrees of durability and swellability. These materials are often polymers. The matrix may contain materials which are not crosslinked, sometimes referred to as co-polymers.
"Polymer" as used herein refers to a natural, synthetic or semi-synthetic molecule, containing a repeatable unit.
"Co-polymer" as used herein refers to a constituent of the matrix which may or may not participate in the crosslinking reaction and is usually not the main constituent of the matrix. A non-limiting example comprises polysaccharides such as dextran and/or a cellulosic polymer such as carboxymethyl cellulose. The co-polymer is preferably not covalently bound to the enzyme or to the matrix material, such as the protein base of the matrix.
"Carrier" as used herein refers to a polymer, a protein, polysaccharide or any other constituent which binds the crosslinking enzyme covalently or non-covalently, either before or during the crosslinking reaction. "Cros slinking Enzyme" as defined herein refers to an enzyme or combination of enzymes that can either directly (e.g. by transglutamination) or indirectly (e.g. through quinone or free radical formation) crosslink substrate groups on polymer strands into a coherent matrix, such as a hydrogel.
According to at least some embodiments of the present invention, there is provided a cross-linked matrix, comprising a substrate polymer crosslinked by a modified enzyme molecule, said modified enzyme molecule having a modification that alters a perceived volume of the enzyme molecules in the crosslinked matrix as the matrix is being formed through cross-linking of said polymer.
Optionally said modified enzyme molecule has a modification that increases an actual size of said modified enzyme molecule. Optionally said modified enzyme molecule has a modification that increases a hydrodynamic volume of said modified enzyme molecule. Optionally said modified enzyme molecule has a modification that modifies an electrostatic charge of said modified enzyme molecule to be of opposite sign to a net charge of said substrate polymer by changing the isoelectric point (pi) of said modified enzyme in comparison to unmodified enzyme. Optionally said modification is of the ε- amino group of lysines of the enzyme through a process selected from the group consisting of succinylation (with succinic anhydride), acetylation (with acetic anhydride), carbamylation (with cyanate), reductive alkylation (aldehydes) and treatment with maleic anhydride. Optionally said modification is of one or more side chains containing carboxylic acids of the enzyme to decrease the number of negative charges.
Optionally said modification comprises covalent or non-covalent attachment of at least one molecule or moiety to said modified enzyme molecule. Optionally said modification comprises covalent attachment of a modifying molecule to said modified enzyme molecule. Optionally said modified enzyme molecule has a reduced diffusion rate and a reduced cross-linking rate in comparison to non-modified enzyme, but has at least similar measured enzyme activity in comparison to non-modified enzyme.
Optionally reduced cross-linking rate is at least 10% of the non-modified enzyme cross -linking rate.
Optionally said modifying molecule comprises a carrier or polymer. Optionally said polymer comprises a synthetic polymer, a cellulosic polymer, a protein or a
polysaccharide. Optionally said cellulosic polymer comprises one or more of
carboxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, or methyl cellulose. Optionally said polysaccharide comprises one or more of dextran, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, hyaluronic acid or a starch derivative.
Optionally said modifying molecule comprises PEG (polyethylene glycol).
Optionally said PEG comprises a PEG derivative. Optionally said PEG derivative comprises activated PEG. Optionally said activated PEG comprises one or more of methoxy PEG (mPEG), its derivatives, mPEG-NHS, succinimidyl (NHS) esters of mPEG (mPEG-succinate-NHS), mPEG- glutarate,-NHS, mPEG- valerate-NHS, mPEG- carbonate-NHS, mPEG- carboxymethyl-NHS, mPEG- propionate-NHS, mPEG- carboxypentyl-NHS), mPEG- nitrophenylcarbonate, mPEG-propylaldehyde, mPEG-
Tosylate, mPEG-carbonylimidazole, mPEG-isocyanate, mPEG-epoxide or a combination thereof. Optionally said activated PEG reacts with amine groups or thiol groups on said enzyme. Optionally the molar ratio of said activated PEG to lysine residues of said activated enzyme is in a range of from 0.5 to 25. Optionally said activated PEG is monofunctional, heterobifunctional, homobifunctional, or multifunctional. Optionally said activated PEG is branched PEGs or multi-arm PEGs. Optionally said activated PEG has a size ranging from 1000 dalton to 40,000 dalton.
Optionally the matrix further comprises a co-polymer that is not covalently bound to said enzyme or to said substrate polymer. Optionally said co-polymer comprises a polysaccharide or a cellulosic polymer. Optionally said polysaccharide comprises dextran, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, hyaluronic acid or a starch derivative. Optionally said cellulosic polymer comprises carboxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, methyl cellulose.
Optionally said modified enzyme molecule is modified by cross-linking said modified enzyme molecule to a plurality of other enzyme molecules to form an aggregate of a plurality of cross-linked enzyme molecules.
Optionally a modification or an extent of modification of said modified enzyme molecule affects at least one property of the matrix. Optionally said at least one property is selected from the group consisting of tensile strength, stiffness, extent of crosslinking of said substrate polymer, viscosity, elasticity, flexibility, strain to break, stress to break, Poisson's ratio, swelling capacity and Young's modulus, or a combination thereof. Optionally an extent of modification of said modified enzyme determines mobility of said modified enzyme in, or diffusion from, the matrix. Optionally said modification of said modified enzyme reduces diffusion coefficient of said modified enzyme in a solution of said modified enzyme and said protein or in a matrix of said modified enzyme and said protein, in comparison to a solution or matrix of non-modified enzyme and said protein. Optionally an extent of modification of said modified enzyme determines one or more matrix mechanical properties. Optionally said modified enzyme molecule shows a greater differential of crosslinking rate in crosslinked polymer than in solution as compared to non-modified enzyme molecule.
According to at least some embodiments of the present invention, there is provided a method for controlling formation of a matrix, comprising modifying an enzyme molecule with a modification that alters a perceived volume of the enzyme molecules in the crosslinked matrix as the matrix is being formed; mixing said modified enzyme molecule with at least one substrate polymer that is a substrate of said modified enzyme molecule; and forming the matrix through crosslinking of said at least one substrate polymer by said modified enzyme molecule, wherein said forming the matrix is at least partially controlled by said modification of said enzyme molecule. Optionally said modification reduces a crosslinking rate of said modified enzyme molecule as an extent of crosslinking of said at least one substrate polymer increases. Optionally said modified enzyme molecule and said at least one substrate polymer are mixed in solution, such that said modification controls extent of crosslinking of said at least one substrate polymer as a viscosity of said solution increases. Optionally said modifying comprises PEGylation of the enzyme at a pH in a range from 7 to 9. Optionally pH of the PEGylation reaction is 7.5 -8.5.
According to at least some embodiments for the method and/or matrix, said at least one substrate polymer comprises a substrate polymer selected from the group consisting of a naturally cross-linkable polymer, a partially denatured polymer that is cross -linkable by said modified enzyme and a modified polymer comprising a functional group or a peptide that is cross-linkable by said modified enzyme. Optionally said at least one substrate polymer comprises gelatin, collagen, casein or albumin, or a modified polymer, and wherein said modified enzyme molecule comprises a modified transglutaminase and/or a modified oxidative enzyme. Optionally said at least one substrate polymer comprises gelatin selected from the group consisting of gelatin obtained by partial hydrolysis of animal tissue or collagen obtained from animal tissue, wherein said animal tissue is selected from the group consisting of animal skin, connective tissue, antlers, horns, bones, fish scales, and a recombinant gelatin produced using bacterial, yeast, animal, insect, or plant systems or any type of cell culture, or any combination thereof. Optionally said gelatin is of mammalian or fish origin. Optionally said gelatin is of type A (Acid Treated) or of type B (Alkaline Treated). Optionally said gelatin is of 250-300 bloom. Optionally said gelatin has an average molecular weight of 75-150 kda.
Optionally said modified transglutaminase comprises modified microbial transglutaminase. Optionally said modified polymer is modified to permit crosslinking by said modified microbial transglutaminase. Optionally said modified oxidative enzyme comprises one or more of tyrosinase, laccase, or peroxidase. Optionally said matrix further comprises a carbohydrate comprising a phenolic acid for being cross-linked by said modified oxidative enzyme as said at least one substrate polymer. Optionally said carbohydrate comprises one or more of arabinoxylan or pectin. Optionally said enzyme molecule is modified through PEGylation and wherein said PEGylation provides immunogenic masking by masking said enzyme molecule from an immune system of a host animal receiving the matrix. Optionally said host animal is human.
According to at least some embodiments, there is provided a method for sealing a tissue against leakage of a body fluid, comprising applying a matrix as described herein to the tissue. Optionally said body fluid comprises blood, such that said matrix is a hemostatic agent.
According to at least some embodiments, there is provided a hemostatic agent or surgical sealant, comprising a matrix as described herein.
According to at least some embodiments, there is provided a composition for sealing a wound, comprising a matrix as described herein. According to at least some embodiments, there is provided a use of the composition for sealing suture or staple lines in a tissue.
According to at least some embodiments, there is provided a composition for a vehicle for localized drug delivery, comprising a matrix as described herein.
According to at least some embodiments, there is provided a composition for tissue engineering, comprising a matrix as described herein, adapted as an injectable scaffold.
According to at least some embodiments, there is provided a method of modifying a composition, comprising: providing a modified enzyme having a cross -linkable functional group and a protein having at least one moiety cross-linkable by said modified enzyme; mixing said modified enzyme and said protein, wherein said modified enzyme cross-links said protein and is also cross-linked to said protein through said cross -linkable functional group.
Non-limiting examples of direct crosslinking enzymes, which directly crosslink substrate groups on polymer strands, include transglutaminases and oxidative enzymes. Examples of transglutaminases include microbial transglutaminase (mTG), tissue transglutaminase (tTG), and Factor XIII. These enzymes can be from either natural or recombinant sources. Glutamine and lysine amino acids in the polymer strands are substrates for transglutaminase crosslinking.
Non-limiting examples of oxidative enzymes are tyrosinase, laccase, and peroxidase. These enzymes crosslink polymers by quinone formation (tyrosinase) or free radical formation (laccase, peroxidase). The quinones and the free radicals then interact with each other or with other amino acids or phenolic acids to crosslink the polymers. The crosslinkable substrates for these enzymes may be any proteins which contain tyrosine or other aromatic amino acids. The substrates may also be carbohydrates which contain phenolic acids such as freulic acid. Such carbohydrates may be arabinoxylan or pectin, for example.
Synthetic or partially synthetic polymers with one or more suitable functional groups could also serve as cross-linkable substrates for any of the above enzymes.
In another embodiment of the present invention, a combination of enzymes is used.
"Polymer strands" or "Polymer chains" as defined herein refers to the substrate polymer for enzyme crosslinking, which according to at least some embodiments of the present invention, preferably belongs to one of the below categories (as non-limiting examples only and without wishing to provide a closed list):
1) Any polymer with substrate groups that are naturally crosslinkable by the enzyme and that is itself naturally crosslinkable by the enzyme. For example, in the case of transglutaminases, this would include protein or polypeptides such as gelatin, collagen, and casein which are naturally crosslinkable by the enzyme.
2) Polymers which contain substrate groups crosslinkable by the enzyme but which are not naturally crosslinkable by the enzyme as a result of their structure. In such cases, the polymer structure must be modified prior to enzyme crosslinking. For example, in the case of transglutaminases, this would include proteins, such as albumin or lactoglobulin, which are not natural substrates for the enzyme because they have a globular structure which hinders the access of the enzyme. These can be made into substrates by partially denaturing the protein using reducing agents, denaturing agents or heat.
3) Polymers, natural or synthetic, that are not substrates for enzyme crosslinking but that have been modified with peptides or functional groups which are substrates of the enzyme, thus rendering the modified polymer crosslinkable by the enzyme. Non-limiting examples of such polymers include any suitable type of protein, which may for example optionally comprise gelatin as noted above. Gelatin may optionally comprise any type of gelatin which comprises protein that is known in the art, preferably including but not limited to gelatin obtained by partial hydrolysis of animal tissue and/or collagen obtained from animal tissue, including but not limited to animal skin, connective tissue (including but not limited to ligaments, cartilage and the like), antlers or horns and the like, and/or bones, and/or fish scales and/or bones or other components; and/or a recombinant gelatin produced using bacterial, yeast, animal, insect, or plant systems or any type of cell culture.
According to preferred embodiments of the present invention, gelatin from animal origins preferably comprises gelatin from mammalian origins and more preferably comprises one or more of pork skins, pork and cattle bones, or split cattle hides, or any other pig or bovine source. More preferably, such gelatin comprises porcine gelatin since it has a lower rate of anaphylaxis. Gelatin from animal origins may optionally be of type A (Acid Treated) or of type B (Alkaline Treated), though it is preferably type A.
Preferably, gelatin from animal origins comprises gelatin obtained during the first extraction, which is generally performed at lower temperatures (50-60° C, although this exact temperature range is not necessarily a limitation). Gelatin produced in this manner will be in the range of 250-300 bloom and has a high molecular weight of at least about 95-100 kDa. Preferably, 275-300 bloom gelatin is used.
A non-limiting example of a producer of such gelatins is PB Gelatins (Tessenderlo Group, Belgium).
According to some embodiments of the present invention, gelatin from animal origins optionally comprises gelatin from fish. Optionally any type of fish may be used, preferably a cold water variety of fish such as carp, cod, or pike, or tuna. The pH of this gelatin (measured in a 10% solution) preferably ranges from 4-6.
Cold water fish gelatin forms a solution in water at 10° C and thus all cold water fish gelatin are considered to be 0 bloom. For the present invention, a high molecular weight cold water fish gelatin is optionally and preferably used, more preferably including an average molecular weight of at least about 95-115 kDa. This is equivalent to the molecular weight of a 250-300 bloom animal gelatin. Cold water fish gelatin undergoes thermoreversible gelation at much lower temperatures than animal gelatin as a result of its lower levels of proline and hydroxyproline. Per 1000 amino acid residues, cold water fish gelatin has 100-130 proline and 50-75 hydroxyproline groups as compared to 135-145 proline and 90-100 hydroxyproline in animal gelatins (Haug Π, Draget KI, Smidsr0d O. (2004). Food Hydrocolloids . 18:203-213).
A non-limiting example of a producer of such a gelatin is Norland Products (Cranbury, NJ).
In some embodiments of the present invention, low endotoxicity gelatin is used to form the gelatin solution component of the gelatin-mTG composition. Such a gelatin is available commercially from suppliers such as Gelita™ (Eberbach, Germany). Low endotoxicity gelatin is defined as gelatin with less than 1000 endotoxicity units (EU) per gram. More preferably, gelatin of endotoxicity less than 500 EU/gram is used.
For very high sensitivity applications, such as with materials that will come into contact with either the spine or the brain, gelatin with endotoxicity of less than 100 EU/gram is preferred, gelatin with less than 50 EU/g is more preferred. Gelatin with endotoxicity less than 10 EU/g is very expensive but could also be used as part of at least some embodiments of the present invention in sensitive applications.
According to some embodiments of the present invention, type I, type II, or any other type of hydrolyzed or non-hydrolyzed collagen replaces gelatin as the protein matter being cross-linked. Various types of collagen have demonstrated the ability to form thermally stable mTG-crosslinked gels.
According to some embodiments of the present invention, a recombinant human gelatin is used. Such a gelatin is available commercially from suppliers such as
Fibrogen™ (San Francisco, CA). Recombinant gelatin is preferably at least about 90% pure and is more preferably at least about 95% pure. Some recombinant gelatins are non- gelling at 10° C and thus are considered to be 0 bloom. For some embodiments of the present invention, a high molecular weight recombinant gelatin is preferably used, more preferably including a molecular weight of at least about 95-100 kDa.
As noted above, the cross-linkable protein preferably comprises gelatin but may also, additionally or alternatively, comprise another type of protein. According to some embodiments of the present invention, the protein is also a substrate for transglutaminase, and preferably features appropriate transglutaminase- specific polypeptide and polymer sequences. These proteins may optionally include but are not limited to synthesized polymer sequences that independently have the properties to form a bioadhesive or polymers that have been more preferably modified with transglutaminase- specific substrates that enhance the ability of the material to be cross-linked by transglutaminase. Non-limiting examples of each of these types of materials are described below.
Synthesized polypeptide and polymer sequences with an appropriate
transglutaminase target for cross-linking have been developed that have transition points preferably from about 20 to about 40°C. Preferred physical characteristics include but are not limited to the ability to bind tissue and the ability to form fibers. Like gelling type gelatins (described above), these polypeptides may optionally be used in compositions that also feature one or more substances that lower their transition point.
Non-limiting examples of such peptides are described in US Patent Nos. 5,428,014 and 5,939,385, both filed by ZymoGenetics Inc, both of which are hereby incorporated by reference as if fully set forth herein. Both patents describe biocompatible, bioadhesive, transglutaminase cross -linkable polypeptides wherein transglutaminase is known to catalyze an acyl-transfer reaction between the γ -carboxamide group of protein-bound glutaminyl residues and the ε -amino group of Lys residues, resulting in the formation of 8-(y-glutamyl) lysine isopeptide bonds.
According to some embodiments, the resultant composition is used as a vehicle for localized drug delivery.
According to some embodiments, the resultant composition is an injectable scaffold for tissue engineering.
According to some embodiments, the composition is a hemostatic composition. According to some embodiments, the composition is a body fluid sealing composition.
The compositions of the present invention preferably provide rapid hemostasis, thereby minimizing blood loss following injury or surgery. "Wound" as used herein refers to any damage to any tissue of a patient that results in the loss of blood from the circulatory system or the loss of any other bodily fluid from its physiological pathway, such as any type of vessel. The tissue can be an internal tissue, such as an organ or blood vessel, or an external tissue, such as the skin. The loss of blood or bodily fluid can be internal, such as from a ruptured organ, or external, such as from a laceration. A wound can be in a soft tissue, such as an organ, or in hard tissue, such as bone. The damage may have been caused by any agent or source, including traumatic injury, infection or surgical intervention. The damage can be life-threatening or non-life- threatening.
Surgical wound closure is currently achieved by sutures and staples that facilitate healing by pulling tissues together. However, very often they fail to produce the adequate seal necessary to prevent fluid leakage. Thus, there is a large, unmet medical need for devices and methods to prevent leakage following surgery, including leaks that frequently occur along staple and suture lines. Such devices and methods are needed as an adjunct to sutures or staples to achieve hemostasis or other fluid-stasis in peripheral vascular reconstructions, dura reconstructions, thoracic, cardiovascular, lung, neurological, and gastrointestinal surgeries. Most high-pressure hemostatic devices currently on the market are nominally, if at all adhesive. Thus, the compositions of the present invention, according to at least some embodiments, overcome these drawbacks and may optionally be used for hemostasis.
As used herein, "about" means plus or minus approximately ten percent of the indicated value.
Other features and advantages of the various embodiments of the invention will be apparent from the following detailed description, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
Figure 1 : Effect of reaction pH and activated PEG concentration on PEGylation products size and distribution;
Figure 2: Effect of reaction time and pH on size and distribution of PEGylation products;
Figure 3: SDS-analysis of PEGylated mTG using various concentrations of PEG-
NHS (2kD);
Figure 4: Elution of mTG and PEGylated mTG from the same crosslinked gelatin gel;
Figure 5: Elution of mTG (left) and PEGylated mTG (right) from different crosslinked gelatin gels;
Figure 6: Burst pressure values for gelatin sealant made with non-PEGylated mTG and 2 types of PEGylated mTG;
Figure 7: SDS-PAGE analysis of conjugation products between mTG and dextran;
Figure 8: SDS-PAGE analysis of PEGylation products of horseradish peroxidase (HRP);
Figure 9: SDS-PAGE analysis of PEGylation products of mTG, using various reactions conditions, the gel demonstrates various degrees of PEGylation;
Figure 10: SDS-PAGE analysis of PEGylation products of mTG, where the reactive PEG is a bifunctional lOkD PEG-NHS;
Figure 11 shows mass to charge spectrum of a typical batch of PEGylated mTG acquired by MALDI-TOF mass spectrometer; and
Figure 12 shows SDS-PAGE analysis of PEGylation products of mTG where PEG reagent to amine ratio is kept constant but reactant concentration is varied. DETAILED DESCRIPTION OF INVENTION
The section headings that follow are provided for ease of description only. It is to be understood that they are not intended to be limiting in any manner. Also, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
Increased perceived volume of enzyme crosslinker in hydrogel
It was found that, in addition to the viscosity of the enzyme-containing polymer solution and the crosslinking density of the partially cross linked solution (availability of reactive groups), the catalytic rate of a crosslinking enzyme within a crosslinked matrix can also be controlled through control of the perceived volume of the enzyme molecule.
According to at least some embodiments of the present invention, such control can optionally and preferably lead to reduced catalytic rate of crosslinking as the matrix approaches a desired mechanical state, by increasing the perceived volume of the enzyme molecule prior to initiation of the crosslinking reaction or during the reaction itself. In this manner, the solidifying matrix traps the size-enhanced enzyme at the desired crosslinking density state and further crosslinking is prevented. Perceived enzyme volume is a function of enzyme molecular weight and hydrodynamic volume, among other factors.
The ultimate extent of crosslinking within a crosslinked matrix can be limited by engineering the enzyme molecules, the matrix material, the crosslinking environment, or some combination of these factors to increase the perceived volume of the enzyme molecules within the crosslinked matrix as the matrix is formed. Without wishing to be limited by a single hypothesis, it is possible that increased perceived enzyme volume results in reduced mobility of the enzyme in the crosslinked matrix. Reducing enzyme mobility to control ultimate crosslinking density is most effective when the enzyme molecules maintain mobility at the early crosslinking reaction stages when the solution viscosity is still low, but lose mobility as crosslinking progresses to increase the solution viscosity, and lose mobility more severely after the initial solid matrix or hydrogel has been formed. Naturally, the precise levels of enzyme mobility within the matrix should be regulated to achieve the crosslinking profile and extent desirable for a particular application. Without wishing to be limited by a single hypothesis, an enzyme with an increased size or increased hydrodynamic volume has a lower diffusion coefficient or mobility in the crosslinked matrix than the non-modified enzyme, resulting in a more limited access to crosslinkable substrates .
Enzyme Molecules with Increased Size and/or Hydrodynamic Volume
A preferred method of reducing the mobility of enzyme molecules in a
crosslinked matrix is increasing the effective size of the enzyme molecules. This can be accomplished by increasing the enzyme molecule molecular weight (MW),
hydrodynamic volume, or both MW and hydrodynamic volume. This is a preferred method because it should not affect the structural composition of the crosslinked matrix.
To be effective for the herein described embodiments of the present invention, enzyme molecule size is preferably increased in a manner that does not eliminate enzyme activity or its ability to crosslink the desired polymer substrate into a solid matrix or hydrogel. The enzyme also preferably retains sufficient activity to form the matrix within an appropriate amount of time. Furthermore, the size-enhanced enzyme molecule also preferably retains sufficient mobility within the crosslinked matrix to catalyze the desired degree of crosslinking prior to ceasing mobility within the matrix.
A number of methods have been identified for increasing enzyme molecule size in crosslinked matrices or hydrogels:
1. Cross link the enzyme to itself (intermolecular crosslinking) in order to from
soluble multi-unit conjugates. An example of this is described in example 18, below.
2. Covalent binding (immobilization) of the enzyme on a carrier:
I. Immobilization to a soluble protein, for example albumin; (Allen TM et al,
1985, JPET 234: 250-254, alpha-Glucosidase-albumin conjugates: effect of chronic administration in mice)
II. Immobilization on a soluble polymer. Preferably, the polymer carrier is larger than the enzyme, where one or more enzyme molecules are immobilized on each molecule of the polymer. It is also possible that a single enzyme molecule will bind to more than one polymer molecule via two or more attachment sites. The carrier may be natural, synthetic or semi- synthetic. Many such applications were developed in order to increase the in vivo stability of enzymes or to reduce immunogenicity. One such family of polymers is cellulose ethers, including but not limited to carboxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, methyl cellulose and others. Such immobilization has previously been accomplished with enzymes such as trypsin (Villaonga et al, 2000, Journal of Molecular Catalysis B: 10, 483-490 Enzymatic Preparation and functional properties of trypsin modified by carboxymethylcellulose) and lysozyme (Chen SH et al, 2003, Enzyme and Microbial Technology 33, 643-649, Reversible immobilization of lysozyme via coupling to reversibly soluble polymer), though such enzyme immobilization has never previously been used to affect mechanical properties of enzyme-crosslinked hydrogels or matrices.
III. Binding to a glycosaminoglycan (GAG), including but not limited to chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, and hyaluronic acid. As above, such binding has been accomplished (Luchter- Wasylewska E et al., 1991, Biotechnology and applied biochemistry 13: 36-47, Stabilization of human prostatic acid phosphatase by coupling with chondroitin sulfate), though never used to affect mechanical properties of enzyme-crosslinked hydrogels or matrices.
IV. Enzymes can also be coupled to polysaccharides, such as dextran and starch derivatives such as hydroxyethyl starch. An example of this can be seen in example 13 where an enzyme was coupled to oxidized dextran.
Addition of one or more moieties to a single enzyme molecule through covalent modification(s). Often, but not always, the said moiety is smaller than the enzyme. An example for such a modification is PEGylation of the crosslinking enzyme, as extensively described below in multiple examples.
Other types of covalent binding. For example, by grafting biotin molecules on the surface of the enzyme (biotinylation) and immobilizing the biotinylated enzyme on avidin or streptavidin containing molecules or polymers. The carrier may be a non crosslinkable soluble polymer whose function is to capture the crosslinking enzyme before or during the crosslinking reaction. Alternatively, the capturing groups, e.g. avidin or streptavidin may be grafted on the crosslinkable polymer itself, resulting in gradual immobilization of the crosslinking enzyme during the crossling reaction on the crosslinkable polymer. 5. Non-covalent binding of the enzyme to a carrier or polymer. For example, electrostatic interactions between the enzyme and the carrier or polymer may provide a stable but non-covalent bond when the net charge of the enzyme has an opposite sign to the net charge of the carrier.
Technologies Related to Increasing the Size of Enzyme Molecules
Though increasing the size of enzymes has been previously disclosed on several occasions, it has never been considered in the context of forming and/or controlling the formation of enzyme crosslinked matrices or hydrogels. Application of size-increased enzymes in crosslinked matrices is entirely novel as the crosslinking reactivity of size increased enzymes in such matrices has not previously been characterized to any degree. Furthermore, the inventors of the present invention have surprisingly demonstrated that isolated enzyme activity of size-enhanced enzyme, as tested in a colorimetric enzyme activity assay, is distinctly different from the crosslinking activity of size-enhanced enzyme in hydrogel formation as indicated by gelation rate. For example, Example 5 describes a comparison of enzyme-catalyzed gelation rate to enzyme activity values measured using a colorimetric assay. PEGylation is described in this Example as a non- limiting, illustrative method for increasing enzyme size.
PEGylation is the covalent attachment of polyethylene glycol (PEG) molecules to enzyme molecules and is a preferred method of increasing enzyme molecule size. The operation of adding such one or more PEG molecules is known as PEGylation.
PEG is a desirable material for use in increasing enzyme size as it is bio-inert and has also demonstrated the ability to limit the immunogenic response to PEGylated implanted or injected molecules. Although it is not known whether PEGylation of enzymes as described herein also causes such immunogenic masking (limited
immunogenic response), without wishing to be limited by a single hypothesis, it is possible that in fact PEGylation of the enzyme does limit the immunogenic response to the enzyme and also possibly, by extension, to the crosslinked matrix.
One method of accomplishing enzyme PEGylation is by reacting the enzyme with activated metoxyl PEG (mPEG) that react with amine groups on the enzyme (amine PEGylation). Non-limiting examples of activated mPEG include succinimidyl (NHS) esters of mPEG (mPEG-succinate-NHS, mPEG- glutarate,-NHS, mPEG- valerate-NHS, mPEG- carbonate-NHS, mPEG- carboxymethyl-NHS, mPEG- propionate-NHS, mPEG- carboxypentyl-NHS), mPEG- nitrophenylcarbonate, mPEG-propylaldehyde, mPEG- Tosylate, mPEG-carbonylimidazole, mPEG-isocyanate, mPEG-epoxide.
The activated mPEGs can be those that react with thiol groups on the enzymes (thiol PEGylation).
The activated PEGs may be monofunctional, heterobifunctional or
homobifunctional .
The activated PEGs may be branched PEGs or multi-arm PEGs.
The size of the activated PEG may range from 1000 dalton to 40,000 dalton
The molar ratio of the activated PEG to lysine groups on the enzyme is from 0.1:1 to 100: 1 and preferably 0.5: 1 to 10: 1
Preferably, the pH of the PEGylation reaction is 7-9. More preferably the pH of the reaction is 7.5 -8.5.
According to a preferred embodiment, the PEGylated enzyme may be further purified from non-reacted enzyme or in order to reduce the size range of the PEGylation products. The purification may be done using size-exclusion chromatography.
Alternatively, or in addition, the purification may be done using ionic chromatography, such as SP-sephrose, Q-sepharose, SM-sepharose or DEAE-sepharose. Alternatively, or in addition, purification from non-reacted enzyme may also be done using dialysis, ultrafiltration or ammonium sulfate fractionation.
Various examples provided below describe the use of PEGylation of
transglutaminases for control of cross-linked hydrogel formation. Example 1 describes PEGylation reaction of mTG with PEG-NHS (5kD). The size and distribution of
PEGylation products is dependent on the PEG to mTG ratio as well as the pH of the reaction.
Example 2 describes PEGylation reaction of mTG with PEG-NHS (5kD). The size and distribution of PEGylation products is dependent on the duration and pH of the reaction.
Example 3 describes PEGylation reaction of mTG with PEG-NHS (2kD). The size and distribution of PEGylation products is dependent on the PEG to mTG ratio.
Example 4 describes a TNBS assay for the determination of the PEGylation extent of various preparations of PEGylated mTG (5kD PEG). The results suggest that the extent of PEGylation depends on the activated PEG: mTG ratio in the reaction. Example 5 describes assays for the determination of activity of PEGylated mTG. The results suggest that PEGylated mTG retains most its activity towards small substrates, such as hydroxylamine and CBZ-Gln-Gly but loses a significant portion of its activity towards larger substrates such as gelatin.
Examples 6 and 7 describe SDS-PAGE analysis of elution profile of mTG and
PEGylated mTG from crosslinked gelatin gels. The results suggest that the PEGylated mTG elutes from the gel more slowly and to a lesser extent than non-PEGylated mTG, possibly due to its larger size or hydrodynamic volume.
Example 8 describes the measurement of activity of mTG that has eluted from crosslinked gelatin gels. The results suggest that non-PEGylated mTG which is eluted from crosslinked gelatin gels retains most of its activity (86% of maximal calculated activity).
Example 9 describes the mechanical testing of gelatin gels crosslinked with PEGylated or non-PEGylated mTG. The results demonstrate that gelatin gels crosslinked with PEGylated mTG are stronger and considerably more flexible than gels cross-linked with non-PEGylated mTG.
Example 10 describes burst pressure testing of various gelatin sealant formulations. The results suggest that gelatin sealants made with PEGylated mTG demonstrate burst pressures results which are comparable to those of sealants made with non-PEGylated mTG.
Example 11 describes use of sealant for staple line reinforcement for in vivo porcine model.
Example 12 describes the effect of non-covalent binding of cross-linking enzyme to insoluble carrier.
Example 13 describes the effect of enzyme modification with oxidized dextran.
Example 14 demonstrates that modification of Horseradish Peroxidase (another crosslinking enzyme) by PEGylation can modify matrices formed by peroxidase cros slinking.
Example 15 demonstrates the effect of partial PEGylation of the cross-linking enzyme.
Example 16 demonstrates that free PEG (PEG molecule placed in solution with the crosslinking enzyme, but not covalently bound to the enzyme) has no effect on gelation. Example 17 illustrates the effect of various mixtures of modified enzyme mixed with non-modified enzyme on gelation.
Example 18 demonstrates the effect of bi-functional PEG-enzyme bridges on gelation.
Example 19 relates to mass spectrometry analysis of PEGylated mTG (microbial transglutaminase).
Example 20 describes PEGylation of mTG at a fixed PEG to amine ratio with various concentrations of reactants, demonstrating the large effect of total reactant concentration on the extent of PEGylation.
Surprisingly it was found in these Examples that while PEGylation reduced the rate at which microbial transglutaminase (mTG) crosslinked gelatin, it did not decrease its activity in the hydroxamate assay, which is a gold standard activity assay for
transglutaminases. These results contradict the background art teachings which indicated that size-enhanced enzyme might be undesirable for use in hydrogel formation as it might have significantly lower efficacy in causing hydrogel formation.
It should be noted that TGases (transglutaminases) are sometimes mentioned in the context of PEGylation in the background art; however, these references teach the use of TGase as a tool for enabling or enhancing site specific PEGylation of other proteins (rather than as a substrate for PEGylation) by catalyzing the transglutamination reaction of glutamyl residues on the said proteins with a primary amine group attached to the said PEG molecules. However, such background art does not teach or suggest PEGylation of TGases themselves in order to alter or control their crosslinking activity or to alter or control the mechanical properties of hydrogel matrices crosslinked by these enzymes.
Reduced Mobility of Crosslinking Enzyme by Coupling onto Crosslinked Matrix
In another embodiment of reducing enzyme mobility in a crosslinked matrix, the enzyme undergoes a binding reaction to the crosslinked matrix itself simultaneous to catalyzing the crosslinking reaction. As the enzyme moves through the polymer solution to crosslink the polymers in a matrix, it is gradually bound to the polymers themselves and thus immobilized in the matrix. For example, biotinylated enzyme can be mixed with a crosslinkable polymer component containing avidin or streptavidin coated polymer. US Patent 6046024 (Method of producing a fibrin monomer using a biotinylated enzyme and immobilized avidin) describes a method of capturing biotinylated thrombin from fibrinogen solution by adding avidin-modified agarose. Though in this case, the agarose was not soluble, it is possible to bind avidin or streptavidin to water soluble polymer as well as described by United States Patent 5026785 (Avidin and streptavidin modified water-soluble polymers such as polyacrylamide, and the use thereof in the construction of soluble multivalent macromolecular conjugates). Biotinylation of transglutaminase and subsequent adsorption to avidin-treated surfaces has been shown to be feasible (Huang XL et al, J. Agric. Food Chem., 1995, 43 (4), pp 895-901). Alternatively, the
crosslinking enzyme may be covalently bound to avidin or streptavidin and the conjugate added to the crosslinking reaction which contains a biotinylated polymer. The
biotinylated may be the crosslinkable polymer itself, e.g. gelatin, or a non-crosslinkable co-polymer such as dextran. Dextran-biotin conjugates of molecular weights of up to 500,000 dalton are available from commercial sources. Reduced Mobility of Crosslinking Enzyme by Electrostatic Interactions in Crosslinked Matrix
In another embodiment of the present invention, enzyme mobility is reduced through reversible binding based on electrostatic interactions between the enzyme and a polymer carrier in which the net charge of the enzyme has an opposite sign to the net charge of the carrier. The enzyme may be pre-incubated with the carrier and added to the crosslinking reaction or it may be bound to the carrier during the cross linking reaction. For example, if the crosslinking enzyme is positively charged at neutral pH it may be electrostatically bound to a negatively charged carrier, for example carboxymethyl cellulose (CMC). The enzyme may be incubated with CMC to allow binding and then the complex added to the crosslinking reaction, or the enzyme and CMC are added separately . In the latter case the enzyme will bind the CMC gradually during the crosslinking reaction. It is also possible to bind the enzyme to the crosslinkable polymer strands themselves during the crosslinking reaction, provided that the crosslinkable polymer bears an opposite sign charge relative to the crosslinking enzyme. Alternatively, the isoelectric point (pi) of the crosslinking enzyme can be shifted such that the enzyme acquires an opposite sign charge than that of the crosslinkable polymer or carrier.
In another embodiment, the crosslinking enzyme is modified in such a way that its isoelectric point (pi) is changed to result in a different net charge on the enzyme at a given pH. Examples of ways to reduce the pi of the enzyme are to modify the ε-amino group of lysines by processes such as but not limited to succinylation (with succinic anhydride), acetylation (with acetic anhydride), carbamylation (with cyanate), reductive alkylation (aldehydes) and treatment with maleic anhydride. This results in decrease in the positive net charge on the protein by up to one charge unit per modified amino acid (except for succinylation which decreases the positive net charge by up to two charge units) and decrease in the pi. Conversely, side chains containing carboxylic acids such as glutamic and aspartic acid may be modified in order to decrease the number of negative charges on the protein and as a result increase the pi. For example it is possible to treat the enzyme with EDC l-Ethyl-3-[3-dimethylaminopropyl]carbodiimide) and ethylene diamine (EDA). EDC activates the carboxylic acid groups and an amide bond is formed between them and EDA. The result is an increase in the positive net charge of the protein and in the pi.
The release of proteins from hydrogels has been linked to electrostatic attraction and repulsion forces between the hydrogel polymer chains and the entrapped protein. It has been suggested that electrostatic repulsion forces increase the diffusion coefficient of the entrapped protein and conversely, electrostatic attraction forces decrease the diffusion coefficient in protein release experiments from recombinant gelatin matrix (Marc Sutter Juergen Siepmann, Wim E. Hennink and Wim Jiskoot, Recombinant gelatin hydrogels for the sustained release of proteins, Journal of Controlled Release Volume 119, Issue 3, 22 June 2007, Pages 301-312)
Changing the pi of the hydrogel polymer chain itself has been suggested as a way to control the release of proteins from that hydrogel. However, the background art involved manipulating electrostatic interactions between proteins entrapped within a hydrogel and the hydrogel chains are concerned with methods of controlling the release rate of the therapeutic proteins from the hydrogel, where the proteins are not themselves involved in the formation of the hydrogel. For at least some embodiments of the present invention, the electrostatic interactions are modified to improve the hydrogel mechanical properties, which may be related to mobility and diffusion coefficient of the enzyme in the hydrogel matrix that the enzyme is crosslinking.
Changing the pi of the entrapped crosslinking enzyme is therefore a novel approach to prevent over cross linking because the diffusion or mobility of the cross linking enzyme in the cross linkable matrix is severely restricted by modification of the pi of the entrapped enzyme rather than of the polymeric hydrogel.
Example I: Effect of reaction pH, and PEG: mTG ratio on size and distribution of PEGylation products
Materials:
Activated PEG: mPEG-glutarate-NHS 5kDa (SunBright ME-050GS, NOF corporation, Japan)
mTG: Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography. Activity: 604 units/ml in 0.2M sodium citrate pH 6
sodium citrate, Hepes , SDS and beta mercaptoethanol were from Sigma Aldrich.
30% Acrylamide/Bis 29:1 and Bio-Safe Coomassie G-250 stain were from Bio-Rad.... Molecular weight marker was Precision Plus Dual Color (Bio-Rad)
1 unit of mTG activity catalyzes the formation of 1.0 μπιοΐ of hydroxamate per min from N-CBZ-Gln-Gly and hydroxylamine at pH 6.0 at 37°C.A set of reactions was set up, each with a volume of 0.2 ml. All reactions contained 15 u/ml mTG, the approprtiate reaction buffer- either 90 mM sodium citarte, pH 6 or lOOmM Hepes pH 7, and various amounts of activated PEG. The PEG-NHS reacts with primary amines in proteins, the epsilon-amine on side chains of lysine residues as well as the amino terminus of proteins. The ratios of PEG to lysine residues in the reaction mix is described in detail below,
The reactions were incubated at 37°C for 1:36 hr and then glycine was added to a final concentration of l lOmM in order to neutralize the excess of activated PEG molecules that have not reacted with the enzyme.
Samples from each reaction were denatured by heating at 90°C in the presence of SDS and beta mercaptoethanol and were analyzed using SDS-PAGE (8% resolving gel, 4% stacking gel, Mini-Protean electrophoresis system, BioRad). To visualize the proteins the gel was stained with Bio-Safe Coomassie G-250 stain followed by destaining with water. The gel was scanned with CanoScan 8800F scanner and the image is shown in Figure 1, showing the effect of reaction pH and activated PEG concentration on
PEGylation products size and distribution. Lane assignments were as follows:
Lane 1 : mTG (control) Lane 2: Molecular size marker (from top to bottom: 250kD, 150 kD, lOOkD, 75 kD, 50kD, 37kD, 25kD)
Lane 3: 53.3 mg/ml activated PEG; 90mM Na citrate pH 6; PEG to lysine ratio 9.15 Lane 4: 26.6 mg/ml activated PEG; 90mM Na citrate pH 6; PEG to lysine ratio 4.59 Lane 5: 13.3 mg/ml activated PEG; 90mM Na citrate pH 6; PEG to lysine ratio 2.30 Lane 6: 53.3 mg/ml activated PEG; lOOmM Hepes pH 7; PEG to lysine ratio 9.15 Lane 7: 26.6 mg/ml activated PEG; lOOmM Hepes pH 7; PEG to lysine ratio 4.59 Lane 8: 13.3 mg/ml activated PEG; lOOmM Hepes pH 7 PEG to lysine ratio 2.30
As can be seen from Figure 1, larger amounts of PEG and increased pH resulted in enzyme having an increased apparent molecular weight on the gel.
Example 2: Effect of reaction pH and duration on size and distribution of
PEGylation products
All reactions contained 15 u/ml mTG.
Materials:
Activated PEG: mPEG-glutarate-NHS 5kDa (SunBright ME-050GS, NOF corporation, Japan)
mTG: Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography. Activity: 604 units/ml in 0.2M sodium citrate pH 6
sodium citrate, Hepes , SDS and beta mercaptoethanol were from Sigma Aldrich.
30% Acrylamide/Bis 29:1 and Bio-Safe Coomassie G-250 stain were from Bio-
Rad.
Molecular weight marker was Precision Plus Dual Color (Bio-Rad)
1 unit of mTG activity will catalyze the formation of 1.0 μπιοΐ of hydroxamate per min from N-CBZ-Gln-Gly and hydroxylamine at pH 6.0 at 37°C.
A set of reactions was set up, each with a volume of 0.2 ml, All reactions contained 15 u/ml mTG, the approprtiate reaction buffer- either 100 mM Hepes, pH 7 or lOOmM Hepes pH 8, and 25 mg/ml PEG-NHS. The ratio of PEG to lysine residues in the reaction mix was 4.59.
The reactions were incubated at room temperature for 2 hr. Samples were taken at various time points as described below and glycine was added to a final concentration of l lOmM in order to neutralize the excess of activated PEG molecules that have not reacted with the enzyme. Samples from each reaction were denatured by heating at 90°C in the presence of SDS and beta mercaptoethanol and were analyzed using SDS-PAGE (8% resolving gel, 4% stacking gel, Mini-Protean electrophoresis system, BioRad). To visualize the proteins the gel was stained with Bio-Safe Coomassie G-250 stain followed by destaining with water. The gel was scanned with CanoScan 8800F scanner and the image is shown in Figure 2, demonstrating the effect of reaction time and pH on size and distribution of PEGylation products. Lane assignments are as follows:
Lane 1: 25 mg/ml activated PEG; lOOmM Hepes pH 8; 15 min reaction time
Lane 2: 25 mg/ml activated PEG; lOOmM Hepes pH 8; 30 min reaction time
Lane 3: 25 mg/ml activated PEG; lOOmM Hepes pH 8; 60 min reaction time
Lane 4: 25 mg/ml activated PEG; lOOmM Hepes pH 8; 120 min reaction time
Lane 5: Molecular size marker (from top to bottom: 250kD, 150 kD, lOOkD, 75 kD, 50kD, 37kD, 25kD)
Lane 6: 25 mg/ml activated PEG; lOOmM Hepes pH 7; 15 min reaction time
Lane 7: 25 mg/ml activated PEG; lOOmM Hepes pH 7; 30 min reaction time
Lane 8: 25 mg/ml activated PEG; lOOmM Hepes pH 7; 60 min reaction time
Lane 9: 25 mg/ml activated PEG; lOOmM Hepes pH 7; 120 min reaction time
As shown in Figure 2, increased reaction time and increased pH resulted in enzyme having an increased apparent molecular weight on the gel.
Example 3: PEGylation of mTG with PEG-NHS (2kD): effect of PEG: mTG ratio on size and distribution of PEGylation products
Materials:
Activated PEG: mPEG-glutarate-NHS 2kDa (SunBright ME-020CS, NOF corporation, Japan)
mTG: Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography. Activity: 604 units/ml in 0.2M sodium citrate pH 6
sodium citrate, Hepes , SDS and beta mercaptoethanol were from Sigma Aldrich.
30% Acrylamide/Bis 29:1 and Bio-Safe Coomassie G-250 stain were from Bio-Rad..
Molecular weight marker was Precision Plus Dual Color (Bio-Rad).
1 unit of mTG activity will catalyze the formation of 1.0 μπιοΐ of hydroxamate per min from N-CBZ-Gln-Gly and hydroxylamine at pH 6.0 at 37°C. Reactions (200 μΐ) contained 15 u/ml mTG, lOOmM Hepes, pH 8 and various concentrations of PEG NHS (2kD). The reactions were incubated at 37 °C for 2 hours, followed by addition of ΙΟμΙ 1.5 M glycine (71mM final concentration) in order to neutralize the PEG-NHS molecules that have not reacted with the enzyme. Samples from each reaction were denatured by heating at 90°C in the presence of SDS and beta mercaptoethanol and were analyzed using SDS-PAGE (8% resolving gel, 4% stacking gel, Mini-Protean electrophoresis system, BioRad). To visualize the proteins the gel was stained with Bio-Safe Coomassie G-250 stain followed by destaining with water. The gel was scanned with CanoScan 8800F scanner and the image is shown in Figure 3, demonstrating SDS-analysis of PEGylated mTG using various concentrations of PEG-NHS (2kD). Lane assignments are as follows:
Lane 1 : Molecular size marker
Lane 2: 1.75 mg/ml PEG-NHS 2kD; PEG to lysine ratio 0.74
Lane 3: 3.5 mg/ml; PEG-NHS 2kD; PEG to lysine ratio 1.48
Lane 4: 7 mg/ml; PEG-NHS 2kD ; PEG to lysine ratio 2.97
Lane 5: 14 mg/ml;; PEG-NHS 2kD ; PEG to lysine ratio 5.93
Lane 6: 28 mg/ml; PEG-NHS 2kD ; PEG to lysine ratio 11.86
Lane 7: 56 mg/ml; PEG-NHS 2kD ; PEG to lysine ratio 23.72
As shown in Figure 3, increased amounts of PEG-NHS resulted in enzyme having an increased apparent molecular weight on the gel.
Example 4: TNBS assay for determining extent of PEGylation
Materials:
Glycine and 5% TNBS solution (picrylsulfonic acid) were from Sigma Aldrich
Sodium bicarbonate was from Frutarom (Israel)
Dilute TNBS solution was prepared by mixing 5% TNBS 1 in 500 in bicarbonate buffer (pH 8.5)
The spectrophotometer was Anthelie Advanced (Secomam)
For calibration curve, the following solutions of glycine were prepared in bicarbonate buffer (pH 8.5): ^g/ml, 2 μg/ml , 4 μg/ml , 8 μg/ml
0.5ml of diluted TNBS solution was mixed with 1 ml of standard glycine solution or sample. The mixture was incubated at 37°C for 2 hours. Next, 0.5 ml of 10% SDS solution and 0.25ml of 1M HCL were added to stop the reaction. The solutions were transferred to a cuvette and the O.D. was read at 335nm using a spectrophotometer.
The percentage of free NH2 groups was determined for each PEGylated mTG based on the calibration curve set up for glycine.
% PEGylation= 100-% of free NH2
Calculated average MW of PEGylated mTG: 38,000+ (% PEGylation: 100 X 18X 5000).
The results are shown in Table 1 below.
Figure imgf000031_0001
Table 1
The above table shows that increased PEGylation results in increased apparent
(calculated) molecular weight of mTG; furthermore, the degree of PEGylation correlated with the reduction in the percentage of free lysine groups, indicating that PEGylation was occurring as expected on the lysine groups. Example 5: assays for measuring the activity of the PEGylated mTG
Materials:
Urea, Na citrate, Na Acetate and calcium chloride were from Sigma Aldrich
Gelatin (Pig skin Type A 275 bloom) was from Gelita The PEGylation reaction (8 ml) contained 15 u/ml mTG, lOOmM HEPES (pH 7) and 14 mg/ml PEG-NHS (5kD). The reaction conditions were similar to those in lane 8 in Fig. 1. The reaction incubated at 37°C for 1:50 hours, followed by addition of 0.4 ml 2.34 M glycine (lOOmM final concentration) in order to neutralize the non-reacted activated PEG. After 15 minutes at room temperature the reaction mix was concentrated to 2 ml using Amicon Ultra-4 Centrifugal Filter Unit MWCO 30,000 (Millipore) and the reaction buffer changed to 0.2 M sodium citrate. The concentrated PEGylated mTG is referred to as 4X, while 2-fold and 4-fold dilutions of it in citrate buffer are referred to as 2X and IX, respectively.
Activity assay using gelatin as a substrate
0.5ml of mTG was mixed with 1 ml of gelatin formulation (25% gelatin, 3.8M urea, 0.15M CaCl2, 0.1M Na acetate pH 6), incubated at 37°C and the gelation time was recorded. By definition, gelation time is the time at which the liquid stops flowing when the reaction tube in inverted. Activity assay using the hydroxamate assay
Reaction A 15 μΐ ΙΧηοη-PEGylated mTG (15u/ml) +135 μΐ citrate buffer
Reaction B 15 μΐ lXPEGylated mTG +135 μΐ citrate buffer
Reaction C 15 μΐ 2XPEGylated mTG +135 μΐ citrate buffer
Reaction D 15 μΐ 4XPEGylated mTG +135 μΐ citrate buffer
1 mL of reaction cocktail was added to each of reaction A-D and the mix was incubated at 37°C for 10 minutes or 20 minutes. At each time point, 0.23 ml of the reaction was added to a tube with 0.5 mL TCA and 0.5 mL.
Hydroxamate reaction substrate cocktail (20 ml, pH 6):
240 mg CBZ-Glu-Gly (Sigma Aldrich)
139 mg hydroxylamine hydrochloride (Sigma Aldrich)
61.5 mg gluthatione reduced (Sigma Aldrich) 4 ml 0.2M Na citrate buffer pH 6
Water to 20 ml The results are shown in Table 2 below.
Figure imgf000033_0001
Table 2
Table 2 above shows that PEGylation of the transglutaminase caused an increase in gelation time at IX PEGylation, but had little effect on the enzyme's activity in the hydroxamate assay (which occurs in free solution, without a hydrogel being formed). Increased amounts of PEGylation actually increased gelation time, presumably by reducing the mobility of the enzyme required for collision with substrate molecules within the forming crosslinked polymer network . Alternate explanations are that PEGylation is conferring a structural alteration to the enzyme's active site such that it cannot accommodate the substrate as efficiently as non-PEGylated enzyme or that the one or more PEG molecules inserted in the vicinity of the active site of the enzyme cause steric hindrance to an approaching substrate molecule. It is possible that the smaller size of substrate or the lack of crosslinked polymer network formation during the reaction in the hydroxamate assay are the reason for the lack of reduction of activity of PEGylated enzyme in this assay. All of these explanations are provided without wishing to be limited by a single hypothesis.
These results support the disparate effects of PEGylation upon formation of a hydrogel than on the enzyme's activity in solution. Without wishing to be limited by a single hypothesis, it is believed that these different effects occur as a result of the increased apparent size and/or perceived volume (other than caused by increased size) of the enzyme, which in turn provide beneficial effects for controlling formation of a hydrogel. In any case, according to at least some embodiments of the present invention, the differential effect of PEGylation enables crosslinking to be controlled during formation of a hydrogel.
Example 6: elution profile of PEGylated and non-PEGylated mTG from gels of gelatin
Materials:
Gelatin (Pig skin type A, 275 bloom) was from Gelita
30% Acrylamide/Bis 29:1 and Bio-Safe Coomassie G-250 stain were from Bio-Rad.... Molecular weight marker was Precision Plus Dual Color (Bio-Rad) A crosslinked gelatin gel was made by mixing 0.67 ml of an enzyme mix comprising of 1:1 mixture of PEGylated mTG (The reaction conditions were similar to those in lane 6 in Fig. 1) and 20 u/ml mTG with 1.33 ml of gelatin solution (25% gelatin, 3.8M urea, 0.15M CaCl2, 0.1M Na acetate pH 6). The resulting gel was wrapped in saran wrap and incubated at 37 °C for 2 hours. Next, the gel was placed in a tube containing 10 ml saline and was incubated for 4 hours at 37°C shaker incubator. Samples were taken every hour. Samples were concentrated using Amicon Ultra-4 Centrifugal Filter Unit MWCO 30,000 (Millipore), denatured by heating at 90°C in the presence of SDS and beta mercaptoethanol and were analyzed using SDS-PAGE (8% resolving gel, 4% stacking gel, Mini-Protean electrophoresis system, BioRad). To visualize the proteins the gel was stained with Bio-Safe Coomassie G-250 stain followed by destaining with water. In order to quantitate the intensities of the bands in SDS-PAGE, the gel was scanned with CanoScan 8800F scanner and the resulting image, shown in Figure 4, was analyzed using Quantity One software (Bio-Rad). The lane assignments are as follows: Lane 1: 10 μΐ sample taken at t= 1 hour
Lane 2: 20 μΐ sample taken at t= 1 hour
Lane 3: 10 μΐ sample taken at t= 4 hour
Lane 4: 20 μΐ sample taken at t= 4 hour
Lane 5: Molecular size marker Lane 6: 7 μΐ mTG+ PEGylated mTG mix
Lane 7: 3 μΐ mTG+ PEGylated mTG mix
Lane 8: 1.5 μΐ mTG+ PEGylated mTG mixture
Figure 4 shows elution of mTG and PEGylated mTG from the same crosslinked gelatin gel. Table 3 shows the relative amounts of transglutaminase eluted from the gel.
Figure imgf000035_0001
Table 3:
*(Total= mTG + PEGylated mTG) Example 7: Elution of different types of PEGylated mTG from crosslinked gelatin gels:
Large scale PEGylation of mTG with different concentrations of 2kD or 5kD PEG-NHS
Activated PEG:
Reagents:
mPEG-glutaryl-NHS, MW 5000 (SunBright ME-050GS, NOF corporation, Japan) mPEG-succinyl-NHS, MW 2000 (SunBright ME-020CS, NOF corporation, Japan) mTG: Ajinimoto active 10% further purified using SP-sepharose ion exchange chromatography.
30% Acrylamide/Bis 29:1 and Bio-Safe Coomassie G-250 stain were from Bio-Rad SDS and beta mercaptoethanol were from Sigma Aldrich
The PEGylation reaction (32 ml) contained 15 u/ml mTG, lOOmM HEPES (pH 8) and various concentrations of PEG-NHS (2kD or 5kD). The reactions were incubated at room temperature for 2.5 hours, followed by addition of 2.2 ml 1.5 M glycine (97mM final concentration) in order to neutralize the non-reacted activated PEG. After 15 minutes of further incubation at room temperature the reaction mix was concentrated down to 8 ml using Vivaspin 20 (Sartorius) while at the same time the reaction buffer was changed to 0.2 M Na citrate pH 6.
1 volume of different PEGylated mTGs (described above) were mixed with 2 volumes of gelatin formulation (25% gelatin, 3.8M urea, 0.15M CaCl2, 0.1M Na acetate pH 6). The mixtures were poured into Teflon coated dog bone shaped molds. After gelation occurred, the gels were taken out of the molds, weighed, placed in a closed test tube to prevent drying and incubated at 37 °C for 3 hours. Next, exactly 5 ml of Na citrate pH 6 were added for each gram of gel, and the test tube was incubated at a 37 °C air shaker at 100 rpm. 0.5ml samples were taken after lhr, 2hr 3 hr and after further incubation for 18 hr at 30°C .
Samples from each timepoint were denatured by heating at 90°C in the presence of SDS and beta mercaptoethanol and were analyzed using SDS-PAGE (8% resolving gel, 4% stacking gel, Mini-Protean electrophoresis system, BioRad). To visualize the proteins the gel was stained with Bio-Safe Coomassie G-250 stain followed by destaining with water. In order to quantitate the intensities of the bands in SDS-PAGE, the gel was scanned with CanoScan 8800F scanner and the resulting image, shown in Figure 5, was analyzed using Quantity One software (Bio-Rad).
The maximal theoretical amount of enzyme that would have been released was loaded on the SDS-PAGE as well and was taken as 100% release. The actual elution samples were ran side by side and the intensities of the bands were calculated relative to the 100% release. In order to quantitate the intensities of the bands in SDS-PAGE, the gel was scanned with CanoScan 8800F scanner and the resulting image was analyzed using Quantity One software (Bio-Rad).
Figure 5 shows elution of mTG (left) and PEGylated mTG (right) from different crosslinked gelatin gels. The lane assignments are given below.
Lane 1: mTG, 100% release reference
Lane 2: mTG released from crosslinked gelatin gel, lhr time -point
Lane 3: mTG released from crosslinked gelatin gel, 2hr time-point
Lane 4: mTG released from crosslinked gelatin gel, 3hr time-point
Lane 5: mTG released from crosslinked gelatin gel, 18hr time-point
Lane 6: PEGylated mTG (7 mg/ ml PEG-NHS, 5kD)- 100% release reference
Lane 7: PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, lhr time-point
Lane 8: PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, 2hr time-point Lane 9: PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, 3hr time-point
Lane 10: PEGylated mTG (7 mg/ ml PEG-NHS, 5kD) released from gelatin gel, 18hr time-point
Figure imgf000037_0001
Table 4: % elution from gelatin gels of different types of PEGylated mTG.
Example 8: Activity of mTG eluted from crosslinked gels
9 ml of Non-PEGylated mTG which was eluted from gelatin gels for 18 hours (see Example 7) was concentrated to 0.47 ml using Vivaspin 20 (MWCO 30,000; Sartorious). The activity of the concentrated enzyme was determined using the hydroxamate assay as described in Example 5.
The measured activity was found to be 3.65 u/ml.
The calculated activity (based on initial activity in the gel of 5 u/ml and % release at 18 hr according to SDS-PAGE in Fig. 5 and its quantitation in Table 4 of 26.7%) is 4.24 u/ml.
Example 9: mechanical testing of gelatin gels crosslinked with PEGylated or non- PEGylated mTG.
Urea, Na citrate, Na Acetate and calcium chloride were from Sigma Aldrich.
Gelatin (Pig skin Type A 275 bloom) was from Gelita.
mTG was from Ajinimoto activa 10% further purified using SP-sepharose ion exchange chromatography. Activity: 604 units/ml in 0.2M sodium citrate pH 6.
PEGylated mTG (either 2kD or 5kD PEG-NHS) with various degrees of PEGylation was prepared as described in Example 7. 1 part of PEGylated mTG solution was mixed with 2 parts of gelatin solution (25% gelatin, 3.8M urea, 0.15M CaCl2, 0.1M Na acetate pH 6). The mixture was poured into a Teflon-coated dog bone shaped mold. After gelation occurred, the gels were taken out of the molds, submerged in saline and incubated at 37°C for 4 hours. The dimensions of the dogbone- shaped gel were then measured using a digital caliper. Control samples were made using 1 part of 15u/ml of non-PEGylated mTG and 2 parts of gelatin solution. For both types of samples, the following testing protocol was followed:
The sample was clamped into a tensile testing system (Instron model 3343) such that the gel sample between the clamps was approximately 12 (width) x 1.9 (thickness) x 20 (length) mm. The precise dimensions of each sample were measured immediately prior to tensile testing and these measured values were used to calculate the material properties of the samples. Following clamping and measuring, tension was applied to each sample at a rate of 0.25 mm/s until a pre-load of 0.025 N was achieved. This was considered the 0% strain point. Following the preload, tensile strain was continuously applied to the sample at a rate of 0.5 mm/s until the sample failed by fracture.
The maximum strain and stress occurred at the fracture point such that the ultimate tensile strain and ultimate tensile stress were recorded at the point of fracture as Strain to break (%) and stress to break (kPa). Elastic modulus was calculated from the linear region between 10% and 30% strain for each sample.
Each type of crosslinked gelatin gel was tested with 5 repetitions and the average and standard deviations are summarized in Table 5.
Table 5
Figure imgf000038_0001
-5 4.25 64.2+5.6 77.7+25.5 159.9+52.6
-5 5.5 47.6+2.8 79.3+16.5 221.7+59.6
Table 5 shows the mechanical testing of various types of PEGylated mTG. The left most column refers to the conditions of PEGylation, given as A-B; the value of A as 7 refers to 7 mg/ml PEG, the value of A as 14 refers to 14 mg/ml PEG, and the value of A as 28 refers to 28 mg/ml PEG; the value of B as 2 refers to 2 kD PEG, while the value of B as 5 refers to 5 kD PEG. As shown, increased amounts of PEG result in increased gelation time and reduced Young's modulus; however, increased PEG size results in increased tensile strength and increased flexibility of the resultant gel . Example 10: Performance of sealant on living tissue using the burst pressure test.
Porcine small intestine tissues were cleaned of residual material and cut into 10 cm pieces. In each piece a 14 gauge needle puncture was made. The tissues were then be soaked in a saline solution and incubated at 37°C. Prior to applying the sealant material, which was prepared as described in Example 7, the tissue was flattened and the application site of each tissue was blotted using a gauze pad. Approximately 0.1-0.2 mL of tested sealant was applied on each application site using a 1 mL syringe. Within 5min of the application the tissue was washed with saline and incubated at 37°C, for 4 hours. Each test group was examined in triplicates or more.
For the burst pressure test, the tissue were placed in the Perspex Box, one side tightly sealed (using a clamp) and the other connected to the pressure meter and hand pump (using a plastic restraint). The Perspex box was filled with saline so that tissue sample is totally submerged. Air was pumped, using the hand-pump at a constant rate (20 mL/min). Burst pressure was determined by the appearance of bubbles.
The results are shown in Figure 6, indicating burst pressure values for gelatin sealant made with non-PEGylated mTG and 2 types of PEGylated mTG. As shown, the median results indicate an increase in burst pressure strength for both types of PEGylated mTG, although a somewhat greater effect is shown for the more moderately PEGylated enzyme. Example 11: Use of sealant for staple line reinforcement for in vivo porcine model
A Covidien EEA circular surgical stapler was used to perform a circular anastomosis in the rectum of a pig.
Surgical sealant comprised of gelatin solution and PEGylated TG was prepared as in example 7, with 28 mg/ml 5 kDa PEG-NHS in a reaction volume of 72 ml. The reaction mix was concentrated using Viva-Spin 20 MWCO 30,000 (Sartorius) to 3 ml, such that the activity of the concentrated PEGylated enzyme was equivalent to 40 u/ml of non-PEGylated enzyme. 4 mL of sealant (comprised of 2.66 ml gelatin solution and 1.33 PEGylated enzyme solution) was applied evenly around the circumference of the rectal staple-line and left to cure for 4 minutes. The animal was then closed.
14 days post-surgery, the pig was sacrificed. The sealed anastomotic area was examined for gross pathology and the sealant was palpated to qualitatively assess its mechanical properties. Result:
The sealant did not undergo significant degradation over the course of the 14 day implantation period. It remained strongly adhered to the staple line, maintaining 100% integrity over the length of the staple line. The sealant material was pliable and flexible, matching the shape and movement of the circular staple-line shape.
No inflammation or abdominal adhesions were noted in the area of the sealant or staple line. The anastomosis was fully healed with no signs of leakage. No strictures were observed in the rectum.
Example 12 - Non-covalent binding of cross-linking enzyme to insoluble carrier
SP sepharose was bound to mTG (microbial transglutaminase) and a gel was made. Gelation occurred in 16-23 minutes with immobilized transglutaminase, while soluble enzyme caused gelation to occur in less than 6 minutes. Immobilization therefore increased the time required for gelation.
500 μΐ washed SP sepharose beads (GE Healthcare) were mixed with 2.7 ml 13.5 mg/ml of purified mTG with 11.55 ml 50mM Na AC pH 5.5 (15ml total). The mixture was incubated in a shaker at room temperature for 20 minutes. The beads were then washed 3 times with 11.5 ml 50mM NaAc pH 5.5, 3 minutes each wash. 70% of the protein was bound to the beads after the washing step. The beads were resuspended in 9.5ml 50mM NaAc pH 5.5 to a final volume of 10 ml. The mTG-loaded beads were mixed with 50mM NaAc pH 5.5 in various compositions in a final volume of 600 μΐ as follows (in parenthesis the amount of bound mTG and the calculated theoretical mTG activity based on the measured activity of 1 mg unbound mTG - 33 hydroxamate units):
A: 292 μΐ beads+ 308 NaAc (1.244 mg/ml= 41 u/ml)
B: 400 μΐ beads + 200 μΐ NaAc (1.704 mg/ml= 56.2 u/ml))
C: 500μ1 beads+ 100 μΐ NaAc (2.13 mg/ml= 70.3 u/ml)
D: 550 μΐ beads + 50 μΐ NaAC (2.34 mg/ml= 77.2 u/ml)
500 μΐ from each reaction A-D were mixed with 1 ml of 25% gelatin solution in sodium acetate buffer with 4.5M urea,) with syringe to syringe mixing. Gelation time was determined as the time in which the gelatin ceased to flow by visual inspection.
Gelation time:
A: about 23 min
B: about 21 min
C: about 20 min
D: about 16 min
Control (unbound mTG 10 u/ml): 5.5 min
Gelation times with bound mTG were significantly slower compared to free enzyme. This suggests that binding of enzyme to a larger scaffold or insoluble carrier slows the mobility of the enzyme in a hydrogel matrix with the result that gelation, a sign of increased mechanical stiffness, is achieved at a later time point through cross-linking by bound enzyme as compared to free (unbound) enzyme. Thus, the enzyme binding resulted in modified mechanical properties of the hydrogel matrix. Example 13 - Enzyme modification with oxidized dextran
This experiment demonstrates that modification of enzyme by binding large soluble molecule can result in modification of mechanical properties.
Methods
1 gram dextran was dissolved in 20ml purified water. 1.3 gram sodium periodate was added and the reaction stirred at room temperature protected from light by aluminum foil for 80 minutes (9:50-11:10).
2 gram glycerol were added to quench the non-reacted periodate.
The reaction was dialyzed 3 times against 1L PuW for 2:00 hr, with water change in between.
Table 6: Conjugation of mTG to oxidized dextran:
Figure imgf000042_0001
The reactions were incubated at room temperature overnight and then were purified by diafiltration using vivaspin 20 (Sartorius). Results
Figure 7 shows SDS-PAGE analysis of conjugation reactions A-D. The following amounts of dextran- conjugated mTG were loaded on a 4-15% Mini-Protean TGX gel (Bio-Rad): 4.35 μg (Reaction A), 4.38 μg (Reaction B), 1.98 μg (Reaction C) and 3 μg (Reaction D). The samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading. The gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio- Rad). The molecular weight marker was Precision Plus (Bio-Rad). The example shows that it is possible to immobilize a crosslinking enzyme, in this case mTG (microbial transglutaminase), on a soluble polymer. Furthermore, at higher dextran:mTG ratios, more molecules of free mTG are converted to high MW conjugates with dextran.
Example 14 - Horseradish Peroxidase PEGylation
This experiment demonstrates that modification of Horseradish Peroxidase (another crosslinking enzyme) by PEGylation can modify matrices formed by peroxidase crosslinking. In another embodiment of the present invention, the crosslinking enzyme is horseradish peroxidase (HRP) and HRP is modified by attachment of PEG molecules to the HRP molecules in order to modify the mechanical properties of the gelatin hydrogel formed by HRP crosslinking.
Methods
Preparation of phenol-modified gelatin (gelatin-Ph): Two grams of high molecular weight gelatin Type A were dissolved in 100 ml 50mM MES (2-(N- morpholino)ethanesulfonic acid; Sigma Aldrich) buffer pH 6. To this 2% w/w solution the following reagents were added: 0.984 gram tyramine (Sigma Aldrich). 0.218 gram NHS (N-Hydroxysuccinimide; Sigma Aldrich), 0.72 gram EDC (l-Ethyl-3-[3- dimethylaminopropyl]carbodiimide; Sigma Aldrich). The reaction was stirred at room temperature for 16 hours, and then dialyzed extensively against distilled water. The dialyzate was freeze dried and the resulting dry foam was dissolved in 0.1M phosphate buffer pH 6.0 to a final volume of 16 ml or 12.5% w/w gelatin. PEGylation of HRP: 2mg/ml HRP Type I (Sigma, St Louis, MO) were reacted with 60 mg/ml PEG-NHS 5kD in lOOmM Hepes pH 8.0 for 2 hours, followed by addition of l lOmM glycine to quench the non-reacted PEG-NHS and 30 minutes further incubation. The PEGylated HRP was purified by extensive dialysis against 25mM phosphate buffer pH 6.0.
HRP and PEGylated HRP dependent gelation of gelatin-Ph: Gelatin component: 5ml gelatin-Ph + 0.5ml 20mM H202 mixed in a glass vial : 4.4 ml were transferred to syringe A. HRP/PEGylated HRP component: 1ml 0.035mg/ml HRPor PEGylated HRP in Syringe B. The gelatin and enzyme components were mixed by syringe to syringe transfer and then incubated at 37°C while being inverted to determine gelation time.
After 20 minutes the gels were weighed, covered with 10ml saline and incubated at 37°C for 16 hours, after which the gels were weighed again to determine swelling ratio.
Results
After mixing, the gelatin and enzyme mixture formed a gel within 3 minutes. SDS- PAGE analysis for HRP and PEGylated HRP proteins can be seen in Figure 8. HRP and PEGylated HRP (20 μg of each) were loaded on a 4-15% Mini-Protean TGX gel (Bio- Rad). The samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading. The gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio- Rad). The molecular weight marker was Precision Plus (Bio-Rad)
The measured swelling ratios are detailed below in Table 7:
Table 7
Figure imgf000044_0001
As can be seen in Table 7 above, the gels made with PEGylated HRP swelled to a larger extent than gels made with non-PEGylated HRP. This demonstrates that the mechanical properties of the gelatin hydrogels formed by the PEGylated (modified) HRP were significantly different than the mechanical properties of the hydrogels formed by the free (unmodified) HRP. Both types of gels were heat resistant and did not dissolve after 1 hour at 80degC.
Example 15 - Effect of Partial PEGylation
Cross-linking enzyme with pegylation to different degrees resulted in different degrees of mechanical properties. This example demonstrates how the mechanical properties of a enzymatically crosslinked hydrogel can be specifically controlled by modulating the hydrodynamic volume, in this case the degree of PEGylation, such that greater hydrodynamic volume (i.e. more PEGylation) results in a more elastic matrix and less hydrodynamic volume (i.e. less PEGylation results in a less elastic matrix. Naturally, the unmodified hydrodynamic volume (i.e. no PEGylation) results in the least elastic matrix. Instron data and SDS-Page gel data are described below with regard to these effects.
Methods
Three PEGylation reactions were performed side by side. The reactions were done at room temperature for 2.5 hr in lOOmM HEPES pH 8.0 using PEG-NHS 5K . Following the reaction, the unreacted excess PEG was neutralized with l lOmM glycine and incubation continued for 30 more minutes.
Reaction A and B had the same PEG:amine ratio but in A, both the mTG and the PEG were 3x more concentrated than in B. Reaction C is similar to A but the PEG:amine ratio was half the ratio in A. The results are shown in Table 8.
Table 8
A B C
PEG cone (mg/ml) 21.00 7.00 10.50
PEG cone (mM) 4.20 1.40 2.10
mTG cone (mg/ml) 5.96 2.00 5.95 mTG amine cone
(mM) 3.15 1.05 3.14
ratio PEG/ amine 1.33 1.33 0.67
Following the completion of these reactions, each resulting solution of PEGylated mTG solution was reacted with a 25% gelatin solution (in sodium acetate buffer with 4.5M urea) at a 1 :2 ratio, mTG solution to gelatin solution, to form a gelatin hydrogel. The mTG activity levels of each PEGylated mTG solution were normalized such that the reaction time with the gelatin was identical for all groups. Following the formation of each hydrogel, it was cultured at 37 °C for 2 hours and then mechanically tested using a tensile testing system.
Results are shown in Figure 9, which is an image of SDS-PAGE analysis of PEGylated mTG. PEGylated mTG from reactions A, B and C (5 μg of each) were loaded on a 6% polyacrylamide gel and subjected to SDS-PAGE. The samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading. The gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio-Rad). The molecular weight marker was Precision Plus (Bio-Rad).
The SDS-PAGE profile shows how reactions A, B, and C resulted in mTG molecules bound with PEG molecules to different degrees such that many PEG molecules are bound to the mTG in A, fewer in B, and even fewer in C.
The varying degrees of PEGylation significantly affect the mechanical properties of the gelatin matrices as can be seen by the below results wherein the most PEGylated mTG, A, results in the most elastic (highest tensile strain at break) hydrogel and the non- PEGylated mTG results in the least elastic hydrogel, with the partially PEGylated mTG groups, B and C, falling out in between in correlation to each groups respective degree of PEGylation. Table 9
Figure imgf000047_0001
Example 16 - Free PEG has no effect on gelation
As a control, Instron results of mechanical properties of gels were tested with and without free PEG. By "free" it is meant that the PEG molecule was placed in solution with the crosslinking enzyme, but was not covalently bound to the enzyme. The results showed that free PEG does not result in the mechanical property modifications brought about by covalent binding of PEG to the cross-linking enzyme (i.e. modification of the enzyme itself with PEG).
Methods
4 ml aliquots of gelatin solution (25% gelatin, 4.5M urea in sodium acetate buffer) with or without 20% PEG 6000 were each mixed with 2ml aliquots of 15 u/ml mTG. 2ml of each resulting solution was poured into dog-bone mold as described for Example 9. The resulting gel was taken out of the mold and incubated in saline at 37°C for 2 hours, followed by tensile testing as described for Example 9.
Results
Table 10
-PEG + 20%
PEG 6000
Modulus 73.72 55.03
(kPa)
Tensile 41.74 30.13
stress at break (kPa)
Tensile 57.7 57
strain at
break (%)
The results of Table 10 demonstrate that the addition of free PEG, a plasticizer, had a minimal or no effect on enzyme crosslinked hydrogel matrix mechanical properties but that these mechanical property modifications are minor in comparison with the modifications achieved by increasing the hydrodynamic volume of the enzyme molecules through the attachment of PEG to the enzyme. In particular, the elasticity (strain to break) of the matrix was not improved at all by addition of free PEG, whereas
PEGylation of the enzyme molecules results in a significant increase in matrix elasticity, as can be seen in several other examples.
Example 17 - Mixed modified/non-modified cross-linking enzyme
Various mixtures of modified enzyme mixed with non-modified enzyme were tested. Different levels of modification of various mechanical properties can be obtained according to the specific mixture.
In another embodiment of the present invention, modified enzyme is used together with unmodified (free) enzyme in order to achieve mechanical modification of an enzyme-crosslinked matrix. Methods
4 ml gelatin solution aliquots (25% gelatin, 4.5M urea, sodium acetate buffer) with or without 20% PEG 6000 were mixed with 2ml 55 u/ml PEGylated mTG with or without additional non-PEGylated mTG and 2ml of each resulting solution was poured into a dog-bone mold as described for Example 9. The resulting gel was taken out of the mold and incubated in saline at 37°C for 24 hours, followed by tensile testing as described for Example 9. Results
Table 11
Figure imgf000049_0001
The results of Table 11 indicate that mechanical properties of an enzyme crosslinked hydrogel can be modified both by using only modified enzyme and also, to a lesser degree, by using a mixture of modified enzyme with free enzyme.
Example 18 - Bi-functional PEG-enzyme bridges
This experiment demonstrated cross-linking of enzyme to itself through a bi- functional PEG bridge. For this example, two or more enzyme molecules can be bound to each other to increase the overall hydrodynamic volume of the enzyme aggregate. One way of accomplishing this is by using a bi-functional molecule that forms a bridge between enzyme molecules. Methods
mTG (15 u/ml, 0.5 mg/ml) was incubated with various concentrations of lOkD bifunctional PEG-NHS in lOOmM Hepes pH8 at room temperature for 2 hours, followed by addition of l lOmM glycine for 30 more minutes to neutralize the excess non-reacted PEG. The specific conditions are shown in Table 12 below. Table 12
Figure imgf000050_0001
Following the reaction, 5μg of enzyme each reaction composition was loaded on a 7.5% polyacrylamide gel and subjected to SDS-PAGE analysis. The samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading. The gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio-Rad). The molecular weight marker was Precision Plus (Bio-Rad).
For mechanical property testing, 4 ml aliquots of gelatin solution (25% gelatin, 4.5M urea, sodium acetate buffer) were mixed with 2ml aliquots of 15 u/ml either free mTG or PEGylated mTG (reaction C). 2ml of the resulting solution were poured into dog-bone molds as described for Example 9. The resulting gel was taken out of the mold and incubated in saline at 37 °C for 24 hours, followed by tensile testing as described for Example 9. Results
The SDS-PAGE results of Figure 10 shows that at relatively low PEG:mTG ratios, some of the mTG was converted to very high MW products, larger than PEGylated products obtained in reactions containing similar concentrations of monofunctional 5kD PEG. This demonstrates that the high MW products consist of multimers of enzyme molecules crosslinked to each other by a bifunctional PEG bridge and demonstrate the efficacy of using bifunctional PEG to modify crosslinker enzyme molecules by binding them to each other.
The mechanical testing results below show that the binding of enzyme crosslinking molecules to each other results in significant modification to the gelatin hydrogels formed by crosslinking with these linked enzyme molecules, as compared with gelatin hydrogels formed by crosslinking with free enzyme molecules. The results are shown in Table 13.
Table 13
Figure imgf000051_0001
Example 19 - Mass spectrometry analysis of PEGylated mTG
Three different batches of PEGylated mTG (microbial transglutaminase enzyme modified with PEG-NHS-5kD) were analyzed by MALDI-TOF mass spectrometry. Figure 11 shows the m/z spectrum of one of these batches.
Mass Spectrometry
Intact molecular mass measurement was performed on a Bruker Reflex III matrix- assisted laser desorption /ionization (MALDI) time-of-flight (TOF) mass spectrometer (Bruker, Bremen, Germany) equipped with delayed ion extraction, reflector and a 337 nm nitrogen laser. Each mass spectrum was generated from accumulated data of 200 laser shots. External calibration for proteins was achieved by using BSA and myoglobin proteins (Sigma, St Louis, MO).
Sample preparation for MALDI-TOF MS - Dry droplet method.
2,5-Dihydroxybenzoic acid (DHB) 0.5 1 of volume of matrix in 2:1 0.1% TriFluoro Acetic acid (TFA) - acetonitrile (ACN) and 0.5 1 of sample solution in Formic
acid/Isopropanol/H20 (1:3:2) were mixed on the target and allowed to air dry. After solvent evaporation the samples the samples were rewashed 1-3 times with 0.1%TFA. Table 14
Figure imgf000052_0001
The results of Table 14 indicate that PEGylation of mTG crosslinking enzyme with 5kDa PEG-NHS reagent results in the binding of multiple PEG molecules to each enzyme molecule.
Example 20 - PEGylation of mTG at a fixed PEG to amine ratio with various concentrations of reactants. This example demonstrates the large effect of total reactant concentration on the extent of PEGylation. When the ratio of PEG:amine was maintained at a fixed value, a correlation between the concentration of reactants (PEG and mTG) and the extent of PEGylation was demonstrated.
Methods
PEGylation of mTG with PEG-NHS-5kD was carried out at room temperature in lOOmM Hepes pH 8.0 for 2.5 hours, followed by addition of l lOmM glycine to neutralize unreacted PEG-NHS. Following the reaction, 5μg of enzyme each reaction composition was loaded on a 6.0% polyacrylamide gel and subjected to SDS-PAGE analysis. The samples contained 0.1% SDS but no reducing agent and were heated at 85°C for 10 minutes before loading. The gel was run at a constant voltage (200V) and the protein bands were visualized by staining with Bio-Safe Coomassie G-250 solution (Bio-Rad). The molecular weight marker was Precision Plus (Bio-Rad).
Reactions were performed according to the below conditions (Table 15): Table 15
Figure imgf000053_0001
Results
The ensuing PEGylated mTG molecules can be seen in the SDS-PAGE lanes shown in Figure 12. As can be seen, even when PEG:Amine ratio was kept fixed, the higher concentration of reactants resulted in product that was more PEGylated.
Although selected embodiments of the present invention have been shown and described individually, it is to be understood that any suitable aspects of the described embodiments may be combined, or indeed a plurality of embodiments may be combined.
In addition, although selected embodiments of the present invention have been shown and described, it is to be understood the present invention is not limited to the described embodiments. Instead, it is to be appreciated that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and the equivalents thereof.

Claims

WHAT IS CLAIMED IS:
1. A cross-linked matrix, comprising a substrate polymer crosslinked by a modified enzyme molecule, said modified enzyme molecule having a modification that alters a perceived volume of the enzyme molecules in the crosslinked matrix as the matrix is being formed through cross-linking of said polymer.
2. The matrix of claim 1, wherein said modified enzyme molecule has a
modification that increases an actual size of said modified enzyme molecule.
3. The matrix of claim 1, wherein said modified enzyme molecule has a
modification that increases a hydrodynamic volume of said modified enzyme molecule.
4. The matrix of claim 1, wherein said modified enzyme molecule has a
modification that modifies an electrostatic charge of said modified enzyme molecule to be of opposite sign to a net charge of said substrate polymer by changing the isoelectric point (pi) of said modified enzyme in comparison to unmodified enzyme.
5. The matrix of claim 4, wherein said modification is of the ε-amino group of lysines of the enzyme through a process selected from the group consisting of succinylation (with succinic anhydride), acetylation (with acetic anhydride), carbamylation (with cyanate), reductive alkylation (aldehydes) and treatment with maleic anhydride.
6. The matrix of claim 4, wherein said modification is of one or more side chains containing carboxylic acids of the enzyme to decrease the number of negative charges.
7. The matrix of any of claims 2-6, wherein said modification comprises covalent or non-covalent attachment of at least one molecule or moiety to said modified enzyme molecule.
8. The matrix of claim 7, wherein said modification comprises covalent attachment of a modifying molecule to said modified enzyme molecule.
9. The matrix of claim 8, wherein said modified enzyme molecule has a reduced diffusion rate and a reduced cross-linking rate in comparison to non-modified enzyme, but has at least similar measured enzyme activity in comparison to non- modified enzyme.
10. The matrix of claim 9, wherein reduced cross-linking rate is at least 10% of the non-modified enzyme cross-linking rate.
11. The matrix of claim 9, wherein said modifying molecule comprises a carrier or polymer.
12. The matrix of claim 11, wherein said polymer comprises a synthetic polymer, a cellulosic polymer, a protein or a polysaccharide.
13. The matrix of claim 12, wherein said cellulosic polymer comprises one or more of carboxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, or methyl cellulose.
14. The matrix of claim 12, wherein said polysaccharide comprises one or more of dextran, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, hyaluronic acid or a starch derivative.
15. The matrix of claim 12, wherein said modifying molecule comprises PEG
(polyethylene glycol).
16. The matrix of claim 15, wherein said PEG comprises a PEG derivative.
17. The matrix of claim 16, wherein said PEG derivative comprises activated PEG.
18. The matrix of claim 17, wherein said activated PEG comprises one or more of methoxy PEG (mPEG), its derivatives, mPEG-NHS, succinimidyl (NHS) esters of mPEG (mPEG-succinate-NHS), mPEG- glutarate,-NHS, mPEG- valerate-NHS, mPEG- carbonate-NHS, mPEG- carboxymethyl-NHS, mPEG- propionate-NHS, mPEG-carboxypentyl-NHS), mPEG- nitrophenylcarbonate, mPEG- propylaldehyde, mPEG-Tosylate, mPEG-carbonylimidazole, mPEG-isocyanate, mPEG-epoxide or a combination thereof.
19. The matrix of claims 17 or 18, wherein said activated PEG reacts with amine
groups or thiol groups on said enzyme.
20. The matrix of any of claims 17-19, wherein the molar ratio of said activated PEG to lysine residues of said activated enzyme is in a range of from 0.5 to 25.
21. The matrix of any of claims 17-20, wherein said activated PEG is monofunctional, heterobifunctional, homobifunctional, or multifunctional.
22. The matrix of any of claims 17-21, wherein said activated PEG is branched PEGs or multi-arm PEGs.
23. The matrix of any of claims 17-22, wherein said activated PEG has a size ranging from 1000 dalton to 40,000 dalton.
24. The matrix of any of the above claims, further comprising a co-polymer that is not covalently bound to said enzyme or to said substrate polymer.
25. The matrix of claim 24, wherein said co-polymer comprises a polysaccharide or a cellulosic polymer.
26. The matrix of claim 25, wherein said polysaccharide comprises dextran,
chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, hyaluronic acid or a starch derivative.
27. The matrix of claim 25, wherein said cellulosic polymer comprises carboxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, methyl cellulose.
28. The matrix of any of the above claims, wherein said modified enzyme molecule is modified by cross -linking said modified enzyme molecule to a plurality of other enzyme molecules to form an aggregate of a plurality of cross-linked enzyme molecules.
29. The matrix of any of the above claims, wherein a modification or an extent of modification of said modified enzyme molecule affects at least one property of the matrix.
30. The matrix of claim 29, wherein said at least one property is selected from the group consisting of tensile strength, stiffness, extent of crosslinking of said substrate polymer, viscosity, elasticity, flexibility, strain to break, stress to break, Poisson's ratio, swelling capacity and Young's modulus, or a combination thereof.
31. The matrix of any of the above claims, wherein an extent of modification of said modified enzyme determines mobility of said modified enzyme in, or diffusion from, the matrix.
32. The matrix of claim 31, wherein said modification of said modified enzyme
reduces diffusion coefficient of said modified enzyme in a solution of said modified enzyme and said protein or in a matrix of said modified enzyme and said protein, in comparison to a solution or matrix of non-modified enzyme and said protein.
33. The matrix of any of the above claims, wherein an extent of modification of said modified enzyme determines one or more matrix mechanical properties.
34. The matrix of any of the above claims, wherein said modified enzyme molecule shows a greater differential of crosslinking rate in crosslinked polymer than in solution as compared to non-modified enzyme molecule.
35. A method for controlling formation of a matrix, comprising modifying an enzyme molecule with a modification that alters a perceived volume of the enzyme molecules in the crosslinked matrix as the matrix is being formed; mixing said modified enzyme molecule with at least one substrate polymer that is a substrate of said modified enzyme molecule; and forming the matrix through crosslinking of said at least one substrate polymer by said modified enzyme molecule, wherein said forming the matrix is at least partially controlled by said modification of said enzyme molecule.
36. The method of claim 35, wherein said modification reduces a crosslinking rate of said modified enzyme molecule as an extent of crosslinking of said at least one substrate polymer increases.
37. The method of claim 36, wherein said modified enzyme molecule and said at least one substrate polymer are mixed in solution, such that said modification controls extent of crosslinking of said at least one substrate polymer as a viscosity of said solution increases.
38. The method of claim 37, wherein said modifying comprises PEGylation of the enzyme at a pH in a range from 7 to 9.
39. The method of claim 38, wherein pH of the PEGylation reaction is 7.5 -8.5.
40. The method or matrix of any of the above claims, wherein said at least one
substrate polymer comprises a substrate polymer selected from the group consisting of a naturally cross -linkable polymer, a partially denatured polymer that is cross -linkable by said modified enzyme and a modified polymer comprising a functional group or a peptide that is cross-linkable by said modified enzyme.
41. The method or matrix of claim 40, wherein said at least one substrate polymer comprises gelatin, collagen, casein or albumin, or a modified polymer, and wherein said modified enzyme molecule comprises a modified transglutaminase and/or a modified oxidative enzyme.
42. The method or matrix of claim 41, wherein said at least one substrate polymer comprises gelatin selected from the group consisting of gelatin obtained by partial hydrolysis of animal tissue or collagen obtained from animal tissue, wherein said animal tissue is selected from the group consisting of animal skin, connective tissue, antlers, horns, bones, fish scales, and a recombinant gelatin produced using bacterial, yeast, animal, insect, or plant systems or any type of cell culture, or any combination thereof.
43. The method or matrix of claim 42, wherein said gelatin is of mammalian or fish origin.
44. The method or matrix of claim 43, wherein said gelatin is of type A (Acid
Treated) or of type B (Alkaline Treated).
45. The method or matrix of claim 44, wherein said gelatin is of 250-300 bloom.
46. The method or matrix of claim 43, wherein said gelatin has an average molecular weight of 75-150 kda.
47. The method or matrix of any of claims 41-46, wherein said modified
transglutaminase comprises modified microbial transglutaminase.
48. The method or matrix of claim 47, wherein said modified polymer is modified to permit crosslinking by said modified microbial transglutaminase.
49. The method or matrix of claims 41-46, wherein said modified oxidative enzyme comprises one or more of tyrosinase, laccase, or peroxidase.
50. The method or matrix of claim 49, wherein said matrix further comprises a
carbohydrate comprising a phenolic acid for being cross-linked by said modified oxidative enzyme as said at least one substrate polymer.
51. The method or matrix of claim 50, wherein said carbohydrate comprises one or more of arabinoxylan or pectin.
52. The method or matrix of any of the above claims, wherein said enzyme molecule is modified through PEGylation and wherein said PEGylation provides immunogenic masking by masking said enzyme molecule from an immune system of a host animal receiving the matrix.
53. The method or matrix of claim 52, wherein said host animal is human.
54. A method for sealing a tissue against leakage of a body fluid, comprising applying a matrix as claimed in any of the above claims to the tissue.
55. The method of claim 54, wherein said body fluid comprises blood, such that said matrix is a hemostatic agent.
56. A hemostatic agent or surgical sealant, comprising a matrix as defined in any of the above claims.
57. A composition for sealing a wound, comprising a matrix as defined in any of the above claims.
58. Use of the composition of claim 57, for sealing suture or staple lines in a tissue.
59. A composition for a vehicle for localized drug delivery, comprising a matrix as defined in any of the above claims.
60. A composition for tissue engineering, comprising a matrix as defined in any of the above claims, adapted as an injectable scaffold.
61. A method of modifying a composition, comprising: providing a modified enzyme having a cross -linkable functional group and a protein having at least one moiety cross -linkable by said modified enzyme; mixing said modified enzyme and said protein, wherein said modified enzyme cross-links said protein and is also cross- linked to said protein through said cross -linkable functional group.
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012017415A2 (en) 2010-08-05 2012-02-09 Lifebond Ltd. Dry composition wound dressings and adhesives
CN102824654A (en) * 2012-09-11 2012-12-19 武汉理工大学 Double-bioenzyme modified blending biological material containing gelatin and chitosan and preparation method and application thereof
WO2014067933A1 (en) * 2012-10-31 2014-05-08 C-Lecta Gmbh Bioactive carrier preparation for enhanced safety in care products and food
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US10202585B2 (en) 2009-12-22 2019-02-12 Lifebond Ltd Modification of enzymatic crosslinkers for controlling properties of crosslinked matrices
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US11642415B2 (en) 2017-03-22 2023-05-09 Ascendis Pharma A/S Hydrogel cross-linked hyaluronic acid prodrug compositions and methods

Families Citing this family (19)

* Cited by examiner, † Cited by third party
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KR101428122B1 (en) * 2006-12-15 2014-08-07 라이프본드 엘티디. Gelatin-transglutaminase hemostatic dressings and sealants
WO2015048355A1 (en) * 2013-09-26 2015-04-02 Northwestern University Poly(ethylene glycol) cross-linking of soft materials to tailor viscoelastic properties for bioprinting
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EP3270985B1 (en) 2015-03-19 2021-02-24 The Brigham and Women's Hospital, Inc. Polypeptide compositions and methods of using the same
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WO2017143298A1 (en) 2016-02-19 2017-08-24 Hampton Creek, Inc. Mung bean protein isolates
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5015677A (en) * 1986-04-25 1991-05-14 Bio-Polymers, Inc. Adhesives derived from bioadhesive polyphenolic proteins
US5026785A (en) 1989-05-12 1991-06-25 The United States Of America As Represented By The Department Of Health And Human Services Avidin and streptavidin modified water-soluble polymers such as polyacrylamide, and the use thereof in the construction of soluble multivalent macromolecular conjugates
US5428014A (en) 1993-08-13 1995-06-27 Zymogenetics, Inc. Transglutaminase cross-linkable polypeptides and methods relating thereto
US5939385A (en) 1993-08-13 1999-08-17 Zymogenetics, Inc. Transglutaminase cross-linkable polypeptides and methods relating thereto
US6046024A (en) 1995-11-09 2000-04-04 E. R. Squibb & Sons, Inc. Method of producing a fibrin monomer using a biotinylated enzyme and immobilized avidin
WO2008076407A2 (en) 2006-12-15 2008-06-26 Lifebond Ltd. Gelatin-transglutaminase hemostatic dressings and sealants
US20080213243A1 (en) * 2006-12-15 2008-09-04 Lifebond Ltd. Hemostatic materials and dressing

Family Cites Families (239)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA896965A (en) 1972-04-04 De Boer Rintje Process for producing a dry gelatin product
US1873580A (en) 1932-08-23 Dustries limited
US2719145A (en) 1955-09-27 Process for effecting complex
US1394654A (en) 1920-12-27 1921-10-25 Donald K Tressler Manufacture of liquid glue
US1844679A (en) 1925-12-07 1932-02-09 Glue Res Corp Glue solution and process of manufacturing same
US1950483A (en) 1931-07-13 1934-03-13 Swift & Co Preparation of glue and the product thereof
US2048499A (en) 1934-04-07 1936-07-21 Deutsche Hydrierwerke Ag Gelatine solutions
US2166074A (en) 1937-04-09 1939-07-11 Sharp & Dohme Inc Gelatinous colloids
US2126305A (en) 1937-06-23 1938-08-09 Eastman Kodak Co Dispersion of gelatin
US2417713A (en) 1940-03-19 1947-03-18 Ilford Ltd Production of gelatin layers
US2398004A (en) 1943-07-20 1946-04-09 Eastman Kodak Co Controlling the isoelectric point of gelatin
US2558065A (en) 1949-05-03 1951-06-26 Linwood F Tice Method of preparing solutions of gelatin in polyhydric alcohols
US2658001A (en) 1950-09-26 1953-11-03 Swift & Co Liquid glue composition
US2803548A (en) 1955-02-07 1957-08-20 Louis Milani Foods Inc Method of making gelatin-containing food preparations which dissolve at room temperature and gel at room temperature
US3220845A (en) 1963-04-10 1965-11-30 Keuffel & Esser Co Epoxy resin impregnated photo base and method of preparation
US3600482A (en) 1970-01-15 1971-08-17 Monsanto Res Corp Method of forming a mat of fibrous gelatin
US3939001A (en) 1973-06-08 1976-02-17 General Foods Corporation Spoonable frozen gelatin dessert concentrate
US3988479A (en) 1975-03-26 1976-10-26 Stephan John T Gelled proteinaceous fish bait and process of preparing same
US4188373A (en) 1976-02-26 1980-02-12 Cooper Laboratories, Inc. Clear, water-miscible, liquid pharmaceutical vehicles and compositions which gel at body temperature for drug delivery to mucous membranes
DE2612726C3 (en) 1976-03-25 1979-03-15 Boehringer Mannheim Gmbh, 6800 Mannheim Stabilized urease
JPS5832576B2 (en) 1976-10-28 1983-07-14 協和醗酵工業株式会社 Method for modifying gelatin
SE415804B (en) 1978-06-21 1980-10-27 Nils Johannes Baecklund SET FOR MEDIUM X-RAY META CONTAIN THE CONTENT OR QUANTITY OF A PRESET-PREPARED SUBSTANCE IN A SAMPLE, AND DEVICE FOR EXECUTING THE SET
US4426443A (en) 1981-08-27 1984-01-17 Dynagel, Incorporated Preparation of hydrolyzed collagen-containing products from non-gelled, liquid hydrolyzed collagen concentrate and gelled products prepared therefrom
US4527906A (en) 1982-12-27 1985-07-09 Venda Jezbera Digital menstrual cycle indicator
US4478822A (en) 1983-05-16 1984-10-23 Merck & Co., Inc. Drug delivery system utilizing thermosetting gels
CA1202904A (en) 1983-11-21 1986-04-08 Brian G. Sparkes Chitosan based wound dressing materials
US4711848A (en) 1984-03-14 1987-12-08 Zymogenetics, Inc. Site specific mutagenesis in alpha-1-antitrypsin
US4605513A (en) 1984-08-08 1986-08-12 Eli Lilly And Company Process for inhibiting peptide carbamylation
JPS61240963A (en) 1985-04-18 1986-10-27 ユニチカ株式会社 Wound covering protective material
JPH0779694B2 (en) 1985-07-09 1995-08-30 カドラント バイオリソ−シズ リミテツド Protection of proteins and similar products
FR2586030B1 (en) 1985-08-07 1987-12-18 Rousselot Cie GELATIN WITH IMPROVED PROPERTIES AND PROCESS FOR THE PREPARATION THEREOF BY FILMING WITH HYDROLYZED GELATIN
EP0302953A1 (en) 1987-08-11 1989-02-15 Deutsche Gelatine-Fabriken Stoess AG Process for preparation of moulded parts from collagen and coleagenous degradation products
DE3726963A1 (en) 1987-08-13 1989-02-23 Stoess & Co Gelatine COLD WATER-SOLUBLE, INSTANTIZED GELATINS AND METHOD FOR THE PRODUCTION THEREOF
US4952618A (en) 1988-05-03 1990-08-28 Minnesota Mining And Manufacturing Company Hydrocolloid/adhesive composition
US4837379A (en) 1988-06-02 1989-06-06 Organogenesis Inc. Fibrin-collagen tissue equivalents and methods for preparation thereof
GB8813161D0 (en) 1988-06-03 1988-07-06 Unilever Plc Emulsions
US4948540A (en) 1988-08-01 1990-08-14 Semex Medical, Inc. Method of preparing collagen dressing sheet material
JPH02255888A (en) 1988-11-08 1990-10-16 Nippon Oil & Fats Co Ltd Crosslinked gelatin gel
US4971954A (en) 1988-11-23 1990-11-20 University Of Medicine And Dentistry Of New Jersey Collagen-based matrices ribose cross-linked
JP2719166B2 (en) * 1989-02-02 1998-02-25 鐘紡株式会社 Hair cosmetic composition
JPH0395109A (en) * 1989-09-08 1991-04-19 Kanebo Ltd Cosmetic for hair
US4931501A (en) 1989-10-20 1990-06-05 Air Products And Chemicals, Inc. Modified poly(vinyl alcohol) containing morpholinoalkylether groups
DE4007668A1 (en) 1990-03-10 1991-09-12 Beiersdorf Ag Gelatin- and water-based hydrogel foams
US5209776A (en) 1990-07-27 1993-05-11 The Trustees Of Columbia University In The City Of New York Tissue bonding and sealing composition and method of using the same
US5059636A (en) 1990-11-13 1991-10-22 Grenga Paul A Tire sealant composition
US6117425A (en) 1990-11-27 2000-09-12 The American National Red Cross Supplemented and unsupplemented tissue sealants, method of their production and use
US6559119B1 (en) 1990-11-27 2003-05-06 Loyola University Of Chicago Method of preparing a tissue sealant-treated biomedical material
US7189410B1 (en) 1990-11-27 2007-03-13 The American National Red Cross Supplemented and unsupplemented tissue sealants, methods of their production and use
US6197325B1 (en) 1990-11-27 2001-03-06 The American National Red Cross Supplemented and unsupplemented tissue sealants, methods of their production and use
US6054122A (en) 1990-11-27 2000-04-25 The American National Red Cross Supplemented and unsupplemented tissue sealants, methods of their production and use
US5480644A (en) 1992-02-28 1996-01-02 Jsf Consultants Ltd. Use of injectable biomaterials for the repair and augmentation of the anal sphincters
US5573934A (en) 1992-04-20 1996-11-12 Board Of Regents, The University Of Texas System Gels for encapsulation of biological materials
DE69328228T2 (en) 1992-04-21 2000-12-21 Ajinomoto Kk Wound medication
IL105529A0 (en) 1992-05-01 1993-08-18 Amgen Inc Collagen-containing sponges as drug delivery for proteins
WO1993024627A1 (en) 1992-06-03 1993-12-09 Case Western Reserve University Bandage for continuous application of biologicals
JP3224607B2 (en) 1992-09-11 2001-11-05 株式会社アズウェル Method for measuring blood coagulation factor XIII activity and reagent kit for the measurement
US5433943A (en) 1992-12-21 1995-07-18 Osipow; Lloyd I. Deodorant and/or antiperspirant compositions
US5549904A (en) 1993-06-03 1996-08-27 Orthogene, Inc. Biological adhesive composition and method of promoting adhesion between tissue surfaces
GB9313501D0 (en) 1993-06-30 1993-08-11 Nycomed Imaging As Improvements in or relating to polymer materials
US5487895A (en) 1993-08-13 1996-01-30 Vitaphore Corporation Method for forming controlled release polymeric substrate
US5441193A (en) 1993-09-23 1995-08-15 United States Surgical Corporation Surgical fastener applying apparatus with resilient film
US5503638A (en) 1994-02-10 1996-04-02 Bio-Vascular, Inc. Soft tissue stapling buttress
JP3433302B2 (en) 1994-02-21 2003-08-04 株式会社ニチロ New gelling material, method for producing the same, gelled food using the same, and method for producing the same
US6704210B1 (en) 1994-05-20 2004-03-09 Medtronic, Inc. Bioprothesis film strip for surgical stapler and method of attaching the same
JPH07328108A (en) 1994-06-10 1995-12-19 Ajinomoto Co Inc Organic tissue adhesive and blood coagulant
US6100053A (en) 1994-08-26 2000-08-08 Novo Nordisk A/S Microbial transglutaminases, their production and use
US5931165A (en) 1994-09-06 1999-08-03 Fusion Medical Technologies, Inc. Films having improved characteristics and methods for their preparation and use
DE69533188T2 (en) 1994-10-11 2005-02-17 Ajinomoto Co., Inc. STABILIZED TRANSGLUTAMINASE AND ENZYMATIC PREPARATION CONTAINING THEREOF
FR2726571B1 (en) 1994-11-03 1997-08-08 Izoret Georges BIOLOGICAL GLUE, PREPARATION METHOD AND APPLICATION DEVICE FOR BIOLOGICAL GLUE, AND HARDENERS FOR BIOLOGICAL GLUE
CA2206852A1 (en) 1994-12-07 1996-06-13 Novo Nordisk A/S Polypeptide with reduced allergenicity
CA2207289C (en) 1994-12-07 2005-04-12 The American National Red Cross Supplemented and unsupplemented tissue sealants, methods of their production and use
GB9501040D0 (en) 1995-01-19 1995-03-08 Quadrant Holdings Cambridge Dried composition
US7253262B2 (en) 1995-01-19 2007-08-07 Quandrant Drug Delivery Limited Dried blood factor composition comprising trehalose
WO1996022366A1 (en) 1995-01-19 1996-07-25 Novo Nordisk A/S Transglutaminases from oomycetes
JP3669390B2 (en) 1995-02-09 2005-07-06 味の素株式会社 Transglutaminase from Bacillus bacteria
US5900245A (en) 1996-03-22 1999-05-04 Focal, Inc. Compliant tissue sealants
WO1996040791A1 (en) 1995-06-07 1996-12-19 Novo Nordisk A/S Modification of polypeptides
US5810855A (en) 1995-07-21 1998-09-22 Gore Enterprise Holdings, Inc. Endoscopic device and method for reinforcing surgical staples
US5702409A (en) 1995-07-21 1997-12-30 W. L. Gore & Associates, Inc. Device and method for reinforcing surgical staples
SE504680C2 (en) 1995-09-19 1997-04-07 Rekordverken Ab Plate with fan and throw wings and recesses for spreading bait and boss from a combine harvester
AU7398196A (en) 1995-10-11 1997-04-30 Fusion Medical Technologies, Inc. Device and method for sealing tissue
JPH09122227A (en) 1995-10-31 1997-05-13 Bio Eng Lab:Kk Medical material and manufacture thereof
US5752974A (en) 1995-12-18 1998-05-19 Collagen Corporation Injectable or implantable biomaterials for filling or blocking lumens and voids of the body
US5814022A (en) 1996-02-06 1998-09-29 Plasmaseal Llc Method and apparatus for applying tissue sealant
DE19604706A1 (en) 1996-02-09 1997-08-14 Merck Patent Gmbh Crosslinking products of biopolymers containing amino groups
WO1997029715A1 (en) 1996-02-20 1997-08-21 Fusion Medical Technologies, Inc. Compositions and methods for sealing tissue and preventing post-surgical adhesions
AU726163B2 (en) 1996-04-04 2000-11-02 Baxter Healthcare Sa Hemostatic sponge based on collagen
US6132765A (en) 1996-04-12 2000-10-17 Uroteq Inc. Drug delivery via therapeutic hydrogels
US5834232A (en) 1996-05-01 1998-11-10 Zymogenetics, Inc. Cross-linked gelatin gels and methods of making them
EP0914168A1 (en) 1996-05-03 1999-05-12 Innogenetics N.V. New medicaments containing gelatin cross-linked with oxidized polysaccharides
JP3407599B2 (en) 1996-07-01 2003-05-19 味の素株式会社 Enzyme preparation for adhesion and method for producing adhesive food
US6066325A (en) 1996-08-27 2000-05-23 Fusion Medical Technologies, Inc. Fragmented polymeric compositions and methods for their use
US7320962B2 (en) 1996-08-27 2008-01-22 Baxter International Inc. Hemoactive compositions and methods for their manufacture and use
US7435425B2 (en) 2001-07-17 2008-10-14 Baxter International, Inc. Dry hemostatic compositions and methods for their preparation
US6063061A (en) 1996-08-27 2000-05-16 Fusion Medical Technologies, Inc. Fragmented polymeric compositions and methods for their use
US6706690B2 (en) 1999-06-10 2004-03-16 Baxter Healthcare Corporation Hemoactive compositions and methods for their manufacture and use
ZA978537B (en) 1996-09-23 1998-05-12 Focal Inc Polymerizable biodegradable polymers including carbonate or dioxanone linkages.
US5752965A (en) 1996-10-21 1998-05-19 Bio-Vascular, Inc. Apparatus and method for producing a reinforced surgical fastener suture line
EP1017794A1 (en) 1997-02-06 2000-07-12 Novo Nordisk A/S Polypeptide-polymer conjugates having added and/or removed attachment groups
US6371975B2 (en) 1998-11-06 2002-04-16 Neomend, Inc. Compositions, systems, and methods for creating in situ, chemically cross-linked, mechanical barriers
AU7245598A (en) 1997-04-03 1998-10-22 California Institute Of Technology Enzyme-mediated modification of fibrin for tissue engineering
WO1998051711A1 (en) 1997-05-14 1998-11-19 Japan As Represented By Director General Of National Institute Of Sericultural And Entomological Science Ministry Of Agriculture, Forestry And Fisherries Chitin beads, chitosan beads, process for preparing these beads, carrier comprising said beads, and process for preparing microsporidian spore
JP3602145B2 (en) 1997-06-03 2004-12-15 イノジェネティックス・ナムローゼ・フェンノートシャップ New pharmaceuticals based on polymers composed of methacrylamide-modified gelatin
US6015474A (en) 1997-06-20 2000-01-18 Protein Polymer Technologies Methods of using primer molecules for enhancing the mechanical performance of tissue adhesives and sealants
ES2296336T3 (en) 1997-06-25 2008-04-16 Novozymes A/S MODIFIED POLYPEPTIDE.
ZA987019B (en) 1997-08-06 1999-06-04 Focal Inc Hemostatic tissue sealants
DE19736420B4 (en) 1997-08-21 2008-04-10 The Whitaker Corp., Wilmington An electrical connector, connector housing, and method of introducing electrical contact into a connector housing
JP3164032B2 (en) 1997-10-01 2001-05-08 日本電気株式会社 Boost circuit
US6190896B1 (en) 1997-11-14 2001-02-20 Bassam M. Fraij Active human cellular transglutaminase
US6762336B1 (en) 1998-01-19 2004-07-13 The American National Red Cross Hemostatic sandwich bandage
JP3981525B2 (en) 1998-01-20 2007-09-26 ハワード・グリーン Transglutaminase linkage of substances to tissues
US6136341A (en) 1998-02-27 2000-10-24 Petito; George D. Collagen containing tissue adhesive
US6107401A (en) 1998-03-26 2000-08-22 Air Products And Chemicals, Inc. Process for producing amine functional derivatives of poly (vinyl alcohol)
JP4137224B2 (en) 1998-03-31 2008-08-20 天野エンザイム株式会社 Protein cross-linking method
WO1999051107A1 (en) 1998-04-08 1999-10-14 Nutreco Aquaculture Research Centre As A method for the modification of protein structure in finish shaped feed pellets, balls or the like in order to achieve shape stability, and feed mass made in accordance with the method
US6047861A (en) 1998-04-15 2000-04-11 Vir Engineering, Inc. Two component fluid dispenser
WO1999057258A1 (en) * 1998-05-01 1999-11-11 The Procter & Gamble Company Laundry detergent and/or fabric care compositions comprising a modified transferase
US6428978B1 (en) 1998-05-08 2002-08-06 Cohesion Technologies, Inc. Methods for the production of gelatin and full-length triple helical collagen in recombinant cells
EP0998311B1 (en) 1998-05-19 2003-11-26 American National Red Cross Hemostatic sandwich bandage comprising a thrombin layer between two fibrinogen layers
US20020015724A1 (en) 1998-08-10 2002-02-07 Chunlin Yang Collagen type i and type iii hemostatic compositions for use as a vascular sealant and wound dressing
DE19838189A1 (en) 1998-08-24 2000-03-02 Basf Ag Stable powdered vitamin and carotenoid preparations and process for their preparation
US7241730B2 (en) 1998-08-27 2007-07-10 Universitat Zurich Enzyme-mediated modification of fibrin for tissue engineering: fibrin formulations with peptides
FR2784296B1 (en) 1998-09-18 2001-01-05 Imedex Biomateriaux DEVICE FOR FORMULATING AND DELIVERING A MIXTURE, PARTICULARLY FOR THE SURGICAL APPLICATION OF THIS MIXTURE
CA2346929A1 (en) 1998-10-13 2000-04-20 Novozymes A/S A modified polypeptide with reduced immune response
US6461849B1 (en) * 1998-10-13 2002-10-08 Novozymes, A/S Modified polypeptide
US6899889B1 (en) 1998-11-06 2005-05-31 Neomend, Inc. Biocompatible material composition adaptable to diverse therapeutic indications
US6454787B1 (en) 1998-12-11 2002-09-24 C. R. Bard, Inc. Collagen hemostatic foam
JP4239412B2 (en) 1998-12-28 2009-03-18 味の素株式会社 Method for producing transglutaminase
US6610043B1 (en) 1999-08-23 2003-08-26 Bistech, Inc. Tissue volume reduction
CA2345779A1 (en) 1999-08-27 2001-03-08 Department Of National Defence Hydrogel wound dressing containing liposome-encapsulated therapeutic agent
JP2003512310A (en) 1999-10-22 2003-04-02 リーフ−フラウプ イーエイチエフ バイオ−ゲルズ ファーマシューティカルス インコーポレイテッド Pharmaceutical composition for treating mucosal epithelial ulcer and / or erosion
US20030035786A1 (en) 1999-11-04 2003-02-20 Medtronic, Inc. Biological tissue adhesives, articles, and methods
US6992172B1 (en) 1999-11-12 2006-01-31 Fibrogen, Inc. Recombinant gelatins
US6425885B1 (en) 1999-12-20 2002-07-30 Ultradent Products, Inc. Hydraulic syringe
JP2003527426A (en) 2000-03-23 2003-09-16 メルク エンド カムパニー インコーポレーテッド Thrombin inhibitors
US6682760B2 (en) 2000-04-18 2004-01-27 Colbar R&D Ltd. Cross-linked collagen matrices and methods for their preparation
JP2001329183A (en) 2000-05-22 2001-11-27 Yuichi Mori Gelling composition
EP1323799A1 (en) 2000-07-28 2003-07-02 Consejo Superior De Investigaciones Cientificas Method for the production of gelatin of marine origin and product thus obtained
US7108876B2 (en) 2001-01-25 2006-09-19 Nutricepts, Inc. Shaped cheese reconstruction with transglutaminase
US6565530B2 (en) 2001-02-28 2003-05-20 Scimed Life Systems, Inc. Immobilizing objects in the body
DE60219775T2 (en) 2001-03-30 2007-12-27 Ajinomoto Co., Inc. BINDER-SERVING ENZYM PREPARATES AND METHOD FOR PRODUCING BONDED, MOLDED FOODS
CA2681952A1 (en) 2001-04-25 2002-10-31 Eidgenoessische Technische Hochschule Zurich Drug delivery matrices to enhance wound healing
US6656193B2 (en) 2001-05-07 2003-12-02 Ethicon Endo-Surgery, Inc. Device for attachment of buttress material to a surgical fastening device
DE60223145T2 (en) 2001-05-16 2008-08-14 Susanna Elizabeth Chalmers WOUND ASSOCIATIONS AND WOUND TREATMENT COMPOSITIONS
WO2002098937A1 (en) 2001-06-01 2002-12-12 Shriners Hospital For Children Polymer composite compositions
US8741335B2 (en) 2002-06-14 2014-06-03 Hemcon Medical Technologies, Inc. Hemostatic compositions, assemblies, systems, and methods employing particulate hemostatic agents formed from hydrophilic polymer foam such as Chitosan
GB2377939B (en) 2001-07-26 2005-04-20 Johnson & Johnson Medical Ltd Apertured sheet materials
IL162369A0 (en) 2001-12-04 2005-11-20 Woolverton Christopher J Storage-stable fibrin sealant
US8501165B2 (en) 2001-12-12 2013-08-06 Promethean Surgical Devices Llc In situ bonds
US6939358B2 (en) 2001-12-20 2005-09-06 Gore Enterprise Holdings, Inc. Apparatus and method for applying reinforcement material to a surgical stapler
AU2003215330B2 (en) 2002-02-21 2008-03-13 Encelle, Inc. Immobilized bioactive hydrogel matrices as surface coatings
WO2003074004A2 (en) 2002-03-01 2003-09-12 Szu-Yi Chou Method of producing antigens
US7101695B2 (en) 2002-03-01 2006-09-05 Szu-Yi Chou Method of producing transglutaminase having broad substrate activity
US7575740B2 (en) 2002-03-22 2009-08-18 Kuros Biosurgery Ag Compositions for tissue augmentation
US6974592B2 (en) 2002-04-11 2005-12-13 Ocean Nutrition Canada Limited Encapsulated agglomeration of microcapsules and method for the preparation thereof
US7005143B2 (en) 2002-04-12 2006-02-28 3M Innovative Properties Company Gel materials, medical articles, and methods
AU2003230933B2 (en) 2002-04-15 2008-01-10 Cook Biotech Incorporated Apparatus and method for producing a reinforced surgical staple line
BR0312132A (en) 2002-06-11 2005-04-05 Celltrix Ab Porous gelatin material, gelatin structures, methods for preparing them and uses for them
US20070082023A1 (en) 2002-06-14 2007-04-12 Hemcon Medical Technologies, Inc. Supple tissue dressing assemblies, systems, and methods formed from hydrophilic polymer sponge structures such as chitosan
US20040106344A1 (en) 2002-06-28 2004-06-03 Looney Dwayne Lee Hemostatic wound dressings containing proteinaceous polymers
US6773156B2 (en) 2002-07-10 2004-08-10 Tah Industries, Inc. Method and apparatus for reducing fluid streaking in a motionless mixer
AU2002950340A0 (en) 2002-07-23 2002-09-12 Commonwealth Scientific And Industrial Research Organisation Biodegradable polyurethane/urea compositions
ATE356838T1 (en) 2002-08-09 2007-04-15 Ottawa Health Research Inst BIOSYNTHETIC MATRIX AND THEIR USE
DE10261126A1 (en) 2002-08-13 2004-03-04 Aventis Behring Gmbh Storage-stable, liquid fibrinogen formulation
CA2498212C (en) 2002-09-10 2012-07-17 American National Red Cross Multi-layered hemostatic dressing comprising thrombin and fibrinogen
WO2004028274A1 (en) 2002-09-26 2004-04-08 Ajinomoto Co., Inc. Enzyme preparation and process for producing food using the same
AU2003275289A1 (en) 2002-09-26 2004-04-19 University Of Maryland Baltimore County Polysaccharide-based polymers and methods of making the same
US20060258560A1 (en) 2002-09-30 2006-11-16 Chunlin Yang Dry tissue sealant compositions
GB2393656B (en) 2002-10-01 2005-11-16 Johnson & Johnson Medical Ltd Enzyme-sensitive therapeutic wound dressings
EP1562630A4 (en) 2002-10-31 2009-02-18 Univ Northwestern Injectible bioadhesive polymeric hydrogels as well as related methods of enzymatic preparation
US6863783B2 (en) 2002-11-14 2005-03-08 The Meow Mix Company Method of producing electrostatically charged gelatin
CA2509622C (en) 2002-12-16 2012-02-21 Gunze Limited Medical film comprising gelatin and reinforcing material
WO2005051979A1 (en) 2003-02-21 2005-06-09 Akzo Nobel N.V. Prevention and/or delay of peptide/protein carbamylation in urea solutions utilizing non-ethylene diamine like compounds
JP2004283371A (en) 2003-03-20 2004-10-14 Nagoya Industrial Science Research Inst Medical material
US7019191B2 (en) 2003-03-25 2006-03-28 Ethicon, Inc. Hemostatic wound dressings and methods of making same
US6923996B2 (en) 2003-05-06 2005-08-02 Scimed Life Systems, Inc. Processes for producing polymer coatings for release of therapeutic agent
WO2004105485A2 (en) 2003-05-30 2004-12-09 Nederlandse Organisatie Voor Toegepast-Natuurwet Enschappelijk Onderzoek Tno Inducible release vehicles
WO2005006991A2 (en) 2003-07-18 2005-01-27 Chiroxia Limited Device and method for fallopian tube occlusion
US7129210B2 (en) 2003-07-23 2006-10-31 Covalent Medical, Inc. Tissue adhesive sealant
US7186684B2 (en) 2003-08-07 2007-03-06 Ethicon, Inc. Hemostatic device containing a protein precipitate
DE10337789A1 (en) 2003-08-14 2005-09-15 3M Espe Ag Single dose syringe for a multi-component material
US7316822B2 (en) 2003-11-26 2008-01-08 Ethicon, Inc. Conformable tissue repair implant capable of injection delivery
WO2005055958A2 (en) 2003-12-09 2005-06-23 Promethean Surgical Devices Llc Improved surgical adhesive and uses therefor
EP1710304A4 (en) 2003-12-24 2008-01-16 Shionogi & Co Process for producing polymer composite of protein
US7109163B2 (en) 2004-01-30 2006-09-19 Ethicon, Inc. Hemostatic compositions and devices
WO2005092914A1 (en) 2004-03-22 2005-10-06 Blue Mountain Technology Development Lab Process for promoting proper folding of human serum albumin using a human serum albumin ligand
WO2005092204A2 (en) 2004-03-22 2005-10-06 Accessclosure, Inc. Apparatus for sealing a vascular puncture
DE102004024635A1 (en) 2004-05-12 2005-12-08 Deutsche Gelatine-Fabriken Stoess Ag Process for the preparation of moldings based on crosslinked gelatin
WO2005120462A2 (en) 2004-06-07 2005-12-22 Callisyn Pharmaceuticals, Inc. Biodegradable and biocompatible crosslinked polymer hydrogel prepared from pva and/or peg macromer mixtures
US20050281799A1 (en) 2004-06-16 2005-12-22 Glen Gong Targeting damaged lung tissue using compositions
US7302083B2 (en) 2004-07-01 2007-11-27 Analogic Corporation Method of and system for sharp object detection using computed tomography images
US7766891B2 (en) 2004-07-08 2010-08-03 Pneumrx, Inc. Lung device with sealing features
WO2006014568A2 (en) 2004-07-08 2006-02-09 Pneumrx, Inc. Lung device with sealing features
WO2006014567A2 (en) 2004-07-08 2006-02-09 Pneumrx, Inc. Pleural effusion treatment device, method and material
EP1809122A1 (en) 2004-08-12 2007-07-25 Nederlandse Organisatie voor toegepast-natuurwetenschappelijk Onderzoek TNO A method for enzymatic cross-linking of a protein, cross-linked protein thus obtained and use thereof
GB0420091D0 (en) 2004-09-10 2004-10-13 Univ Nottingham Trent Medical implant materials
US20060100138A1 (en) 2004-11-10 2006-05-11 Olsen David R Implantable collagen compositions
FR2878533B1 (en) 2004-11-26 2007-04-27 Univ Cergy Pontoise BIOMATERIAL CAPABLE OF SUCCESSIVELY MAKING A TRANSITION SOLUTION / GEL AND A TRANSITION GEL / SOLUTION
JP2008529663A (en) 2005-02-09 2008-08-07 チルドレンズ メディカル センター コーポレイション Devices that mix and deliver fluids for tissue recovery
EP1857494B1 (en) 2005-02-14 2013-06-26 Medgel Corporation Hydrogel for medical use
US7485323B2 (en) 2005-05-31 2009-02-03 Gelita Ag Process for making a low molecular weight gelatine hydrolysate and gelatine hydrolysate compositions
AU2006259080A1 (en) 2005-06-15 2006-12-21 Novo Nordisk Health Care Ag Transglutaminase mediated conjugation of growth hormone
CA2616865C (en) 2005-07-28 2014-07-08 Carnegie Mellon University Biocompatible polymers and methods of use
DE102005041927B4 (en) 2005-09-03 2013-02-28 Bosch Rexroth Aktiengesellschaft Active line filter
DE102005054940A1 (en) 2005-11-17 2007-05-24 Gelita Ag Composite material, in particular for medical use, and method for its production
EP1968617A4 (en) 2005-12-06 2012-05-02 Tyco Healthcare Biocompatible tissue sealants and adhesives
CA2573472A1 (en) 2006-01-23 2007-07-23 Tyco Healthcare Group Lp Biodegradable hemostatic compositions
JP4663548B2 (en) 2006-02-24 2011-04-06 株式会社小糸製作所 Vehicle headlamp lamp unit
US20070246505A1 (en) 2006-04-24 2007-10-25 Medical Ventures Inc. Surgical buttress assemblies and methods of uses thereof
KR20070104748A (en) 2006-04-24 2007-10-29 박현진 Film-forming composition for hard capsules comprising fish gelatin and its preparation method
EP2722425B1 (en) 2006-04-24 2016-01-20 Coloplast A/S Gelatin non-woven structures produced by a non-toxic dry solvent spinning process
WO2007134118A2 (en) 2006-05-09 2007-11-22 Chulso Moon Protein based composition and methods of using same
WO2008000655A2 (en) 2006-06-27 2008-01-03 Robert Bosch Gmbh Method and device for avoiding interference in a radio transmission system
DE102006033167A1 (en) 2006-07-10 2008-01-24 Gelita Ag Use of gelatin and a crosslinking agent for the preparation of a crosslinking medical adhesive
DE102006033168A1 (en) 2006-07-10 2008-01-17 Gelita Ag Use of gelatin and a crosslinking agent for the preparation of a crosslinking therapeutic composition
TWI436793B (en) 2006-08-02 2014-05-11 Baxter Int Rapidly acting dry sealant and methods for use and manufacture
WO2008073938A2 (en) 2006-12-11 2008-06-19 Pluromed, Inc. Perfusive organ hemostasis
US8057426B2 (en) 2007-01-03 2011-11-15 Medtronic Vascular, Inc. Devices and methods for injection of multiple-component therapies
US8088095B2 (en) 2007-02-08 2012-01-03 Medtronic Xomed, Inc. Polymeric sealant for medical use
BRPI0807558A2 (en) 2007-02-22 2014-07-01 Pluromed Inc Use of Reverse Thermosensitive Polymers to Control the Flow of Biological Fluid Subsequent to a Medical Procedure
US8189557B2 (en) 2007-02-23 2012-05-29 Texas Instruments Incorporated Secondary synchronization channel design for OFDMA systems
SI2170602T1 (en) 2007-07-20 2012-03-30 Bayer Innovation Gmbh Soil cover film with barrier functionality
WO2009026158A2 (en) 2007-08-16 2009-02-26 Carnegie Mellon University Inflammation-regulating compositions and methods
WO2009036014A2 (en) 2007-09-10 2009-03-19 Boston Scientific Scimed, Inc. Medical devices with triggerable bioadhesive material
EP2229147A2 (en) 2007-12-03 2010-09-22 The Johns Hopkins University Methods of synthesis and use of chemospheres
WO2009075329A1 (en) * 2007-12-11 2009-06-18 Fujifilm Corporation Gelatin composition with controlled degradability
WO2009105614A2 (en) 2008-02-22 2009-08-27 Dermal Technologies, Llc Compositions for tissue augmentation
CN102014973A (en) 2008-02-29 2011-04-13 弗罗桑医疗设备公司 Device for promotion of hemostasis and/or wound healing
AU2009220808B2 (en) 2008-03-03 2014-01-16 Omrix Biopharmaceuticals Ltd. A gelatin sponge comprising an active ingredient, its preparation and use
US20100008989A1 (en) 2008-06-12 2010-01-14 Ishay Attar Process for manufacture of gelatin solutions and products thereof
WO2009153748A2 (en) 2008-06-18 2009-12-23 Lifebond Ltd Methods and devices for use with sealants
EP2310459B1 (en) 2008-06-18 2014-10-22 Lifebond Ltd Improved cross-linked compositions
EP2303341A2 (en) 2008-06-18 2011-04-06 Lifebond Ltd A method for enzymatic cross-linking of a protein
US9216188B2 (en) 2008-09-04 2015-12-22 The General Hospital Corporation Hydrogels for vocal cord and soft tissue augmentation and repair
EP2442834A2 (en) 2009-06-15 2012-04-25 Technion Research and Development Foundation, Ltd. Reinforced surgical adhesives and sealants and their in-situ application
CN102802683B (en) 2009-06-16 2015-11-25 巴克斯特国际公司 Sthptic sponge
CA2784432C (en) 2009-12-16 2019-01-15 Baxter Healthcare S.A. Hemostatic sponge
CN102711853B (en) 2009-12-22 2015-05-20 生命连结有限公司 Modification of enzymatic crosslinkers for controlling properties of crosslinked matrices
US9297464B1 (en) 2014-09-11 2016-03-29 Beto Engineering & Marketing Co., Ltd. Air pump having pivotal attachment

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5015677A (en) * 1986-04-25 1991-05-14 Bio-Polymers, Inc. Adhesives derived from bioadhesive polyphenolic proteins
US5026785A (en) 1989-05-12 1991-06-25 The United States Of America As Represented By The Department Of Health And Human Services Avidin and streptavidin modified water-soluble polymers such as polyacrylamide, and the use thereof in the construction of soluble multivalent macromolecular conjugates
US5428014A (en) 1993-08-13 1995-06-27 Zymogenetics, Inc. Transglutaminase cross-linkable polypeptides and methods relating thereto
US5939385A (en) 1993-08-13 1999-08-17 Zymogenetics, Inc. Transglutaminase cross-linkable polypeptides and methods relating thereto
US6046024A (en) 1995-11-09 2000-04-04 E. R. Squibb & Sons, Inc. Method of producing a fibrin monomer using a biotinylated enzyme and immobilized avidin
WO2008076407A2 (en) 2006-12-15 2008-06-26 Lifebond Ltd. Gelatin-transglutaminase hemostatic dressings and sealants
US20080213243A1 (en) * 2006-12-15 2008-09-04 Lifebond Ltd. Hemostatic materials and dressing

Non-Patent Citations (29)

* Cited by examiner, † Cited by third party
Title
ALLEN TM ET AL., JPET, vol. 234, 1985, pages 250 - 254
BABIN H; DICKINSON E, FOOD HYDROCOLLOIDS, pages 204 - 210
BAUER N; KOEHLER P; WIESER H; SCHIEBERLE P: "Studies on Effects of Microbial Transglutaminase on Gluten Proteins of Wheat II Rheological Properties", CEREAL CHEM., vol. 80, no. 6, pages 787 - 790
BUCHTA C; HEDRICH HC; MACHER M; HOCKER P; REDL H, BIOMATERIALS, vol. 26, 2005
BURZIO LA, WAITE JH, BIOCHEMISTRY, vol. 39, 2000, pages 11147 - 53
CHEN SH ET AL., ENZYME AND MICROBIAL TECHNOLOGY, vol. 33, 2003, pages 643 - 649
CHEN T; PAYNE GF ET AL., J BIOMED MATER RES B APPL BIOMATER, vol. 77, 2006, pages 416 - 22
CHEN TH; PAYNE GF ET AL., BIOMATERIALS, vol. 24, 2003, pages 2831 - 2841
DRURY J L ET AL: "Hydrogels for tissue engineering: scaffold design variables and applications", BIOMATERIALS, ELSEVIER SCIENCE PUBLISHERS BV., BARKING, GB, vol. 24, no. 24, 1 November 2003 (2003-11-01), pages 4337 - 4351, XP004446078, ISSN: 0142-9612, DOI: DOI:10.1016/S0142-9612(03)00340-5 *
EHRBAR M; RIZZI SC; HLUSHCHUK R; DJONOV V; ZISCH AH; HUBBELL JA; WEBER FE; LUTOLF MP, BIOMATERIALS, vol. 28, 2007, pages 3856 - 66
HAUG U; DRAGET KI; SMIDSRØD O, FOOD HYDROCOLLOIDS, vol. 18, 2004, pages 203 - 213
HU BH; MESSERSMITH PB, J. AM. CHEM. SOC., vol. 125, no. 47, 2003, pages 14298 - 14299
HUANG XL ET AL., J. AGRIC. FOOD CHEM., vol. 43, no. 4, 1995, pages 895 - 901
IWATA, H.; MATSUDA, S.; MITSUHASHI, K.; ITOH, E.; LKADA, Y, BIOMATERIALS, vol. 19, 1998, pages 1869 - 76
JACKSON MR, AM J SURG, vol. 182, 2001, pages 1S - 7S
LIM, D. W.; NETTLES, D. L.; SETTON, L. A.; CHILKOTI, A, BIOMACROMOLECULES, vol. 9, 2008, pages 222 - 30
LUCHTER-WASYLEWSKA E ET AL., BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY, vol. 13, 1991, pages 36 - 47
MARC SUTTEI; JUERGEN SIEPMANN; WIM E. HENNINK; WIM JISKOOT: "Recombinant gelatin hydrogels for the sustained release of proteins", JOURNAL OF CONTROLLED RELEASE, vol. 119, no. 3, 22 June 2007 (2007-06-22), pages 301 - 312, XP022087330, DOI: doi:10.1016/j.jconrel.2007.03.003
MCDERMOTT MK; PAYNE GF ET AL., BIOMACROMOLECULES, vol. 5, 2004, pages 1270 - 1279
MCDOWELL LM; BURZIO LA; WAITE JH; SCHAEFER JJ, BIOL CHEM, vol. 274, 1999, pages 20293 - 5
OTANI Y; TABATA Y; IKADA Y, ANN THORAC SURG, vol. 67, 1999, pages 922 - 6
OTANI, Y.; TABATA, Y.; IKADA, Y., BIOMATERIALS, vol. 19, 1998, pages 2167 - 73
SAKAI ET AL.: "found that a larger quantity of covalent cross-linking between phenols was effective for enhancement of the mechanical stability, however, further cross-linking Synthesis and characterization of both ionically and enzymatically crosslinkable alginate", ACTA BIOMATER, vol. 3, 2007, pages 495 - 501
SANBORN TJ; MESSERSMITH PB; BARRON AE, BIOMATERIALS, vol. 23, 2002, pages 2703 - 10
SPERINDE J; GRIFFITH L, MACROMOLECULES, vol. 33, 2000, pages 5476 - 5480
SPOTNITZ WD, AM J SURG, vol. 182, 2001, pages 8S - 14S
STRAUSBERG RL; LINK RP, TRENDS BIOTECHNOL, vol. 8, 1990, pages 53 - 7
SUNG HW; HUANG DM; CHANG WH; HUANG RN; HSU JC, J BIOMED MATER RES, vol. 46, 1999, pages 520 - 30
VILLAONGA ET AL., JOURNAL OF MOLECULAR CATALYSIS B, vol. 10, 2000, pages 483 - 490

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10202585B2 (en) 2009-12-22 2019-02-12 Lifebond Ltd Modification of enzymatic crosslinkers for controlling properties of crosslinked matrices
WO2012017415A2 (en) 2010-08-05 2012-02-09 Lifebond Ltd. Dry composition wound dressings and adhesives
CN104080468A (en) * 2011-11-02 2014-10-01 哈尔西恩股份有限公司 Method and composition for wound treatment
JP2015500388A (en) * 2011-12-19 2015-01-05 ディラホア アクチエボラゲット Non-anticoagulant glycosaminoglycans containing disaccharide repeat units and their medical uses
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WO2014067933A1 (en) * 2012-10-31 2014-05-08 C-Lecta Gmbh Bioactive carrier preparation for enhanced safety in care products and food
US11642415B2 (en) 2017-03-22 2023-05-09 Ascendis Pharma A/S Hydrogel cross-linked hyaluronic acid prodrug compositions and methods
CN114073788A (en) * 2020-08-20 2022-02-22 青叶化成株式会社 Liquid medical material
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